We will try to cover every base here, live vs. prekilled, feeding hatchlings, feeding issues etc.
Myths abound when it comes to the nature, care and keeping of reptiles and amphibians. One of the most common is related to the feeding of live prey. Many people, including experienced herpetologists, herpetoculturists, pet store owners, store employees, and authors of reptile books say that reptiles and amphibians (collectively known as herps) will only eat live prey.
On the contrary. Most herps found in the pet trade can easily be converted over to feeding on killed prey, especially those herps who are already feeding on live rodents and rabbits. Reptiles and amphibians who normally feed on a variety of prey in the wild such as invertebrates, small mammals, amphibians and birds will take killed prey in captivity if offered properly. Herps whose main dietary staples include birds, fish and swimming amphibians and insects are more difficult to convert to feeding on killed and some may never do so.
The types of herps who can be easily converted to killed prey include snakes such as king, milk, gopher, pine, bull, boas, pythons (except the more difficult green tree pythons and emerald boas), corn and rat snakes. Lizards who will eat killed prey include blue-tongue and other omnivorous skinks, many of the geckos, bearded dragons, water dragons, sailfin lizards, basilisks, monitors of all types, and teiids (tegus, agamas). Large rodent-eating amphibians such as bullfrogs and ornate horned frogs will also take prekilled prey.
Why Feed Killed?
The most common arguments presented for feeding live prey are that "feeding live is more natural for the animal - after all, no one kills their food in the wild" and "I like to give my animal a chance to hunt and kill because it really likes it."
The fact, however, is that captivity is not a natural state. Our reptiles and amphibians are not spending their days searching for food, hiding from predators, searching out favored microhabitats while avoiding aggressive members of their own species, hiding, vulnerable to predation and attack, during their shed periods. Instead they are housed (or should be!) in a comfy enclosure with all of their habitat needs met. If we wanted our animals to enjoy a natural state, we would never have acquired them.
As for needing the "thrill of the kill," that is anthropomorphism at its worst. What our reptiles and amphibians need is a large enough environment outfitted properly to give it enough mental and physical stimulation. For reptiles who are handleable, handling and that opportunity to be out of their enclosure provides the exercise and stimulation that they need, not chasing a rat or mouse around a small rectangular box.
Feeding killed is also safer for the reptile or amphibian. An animal who is not hungry will not eat. It will ignore whatever is going on around it. A prey animal left alone in a tank with a predator, however, is not so relaxed about the whole thing. Mice and chicks are usually terrified, spending their time cowering in a corner or trying to find a place to hide. Rats, however, come from bolder, and hungrier, stock. If left alone long enough with a disinterested predator, they will begin to eat whatever is around: your snake or lizard. Crickets and mealworms are similarly fearless and hungry. Rats have eaten their way into snakes, devouring the skin and flesh off their backs, exposing long stretches of backbone, even quite literally eviscerating them. Even crickets and mealworms will gnaw away at the skin and seek moisture from the eyes of healthy herps when left unattended in an enclosure without proper food and moisture for them. One of the most tragic things a vet or experienced herper sees is an otherwise healthy reptile or amphibian that has to be put down or is already dead from such prey feeding practices.
Live prey may also fight back during a feeding session causing severe injuries. Claws and teeth can bite through the mouth area, puncture eyes, cut through tongue sheaths, and puncture or slice through a coil of the predator's body.
There are those who will argue that it does not happen in the wild. There are also those who will argue that it does happen in the wild and that, being a natural occurrence, should not be avoided in captivity. It does happen in the wild. We don't see much evidence of it as the injured or crippled predator manages to hide away before dying or is itself preyed upon by another predator before dying or is scavenged after dying. I responded to a call where I found a wild gopher snake whose jaw had been fractured and half its tongue bitten off by prey who had successfully fought off a feeding attempt, its grossly swollen and bloodied tongue sheath dangling from the broken, crooked jaw.
Whether it happens or not, however, is immaterial. We are responsible for the health and well-being of our animals in captivity. That means keeping them properly housed, heated, humidified and fed. And that means keeping them safe from avoidable harm.
Humanely Killing Prey
There are a number of ways of killing prey most of which involve the rapid separation of the vertebrae at the neck just below the base of the skull. Some people can do this quickly by hand; others recommend the use of a spoon. Still others recommend blunt trauma to effect immediate unconsciousness and death.
There is, however, an easier way that is less traumatic to the mammalian prey animal, ensures immediate unconsciousness followed almost instantaneously by death. This is done by setting up a tank, be it a deep aquarium, bucket or rubber or plastic wastebasket set aside for this use, and filling it half full of carbon dioxide (CO2) gas. Once the tank is thus 'charged,' the prey animal is placed inside (be careful to not get your head too close to the tank as the gas is quite capable of knocking you unconscious, too). It is immediately rendered unconscious and is killed within a few minutes. The killed prey can then be removed (it is recommended that you use long kitchen or barbecue tongs), and set aside to be fed out or frozen for later use. Let the gas dissipate outside by setting the tank outside for a couple of hours.
You can get CO2 relatively inexpensively in a gaseous form in tanks from welder's supply shops, and in solid form (as dry ice) from ice houses; these suppliers may be found in the telephone yellow pages.
Sources of Killed Prey
Live prey may be purchased as usual, killed humanely, and then fed out. Have an experienced herper show you how to quickly kill prey by breaking the neck. If you are unsure how to do it, you may cause injury and pain rather than death, so please do not experiment.
While some people have no problem with the feeding of prey and are interested in feeding killed prey, they may not be able to do it themselves. An increasing number of pet stores are selling prekilled prey or may kill upon request. If you have a large number of reptiles or just a few big eaters, there are many mail order prey suppliers who ship out bulk orders of frozen prey. Their prices are less expensive than pet store prices, even when adding in the cost of shipping. It takes much less room to store 100 frozen adult mice in your freezer than it does to house, feed and care for properly the same number of live mice. Buying frozen can save you enough money to enable you to provide better care and housing for your herp, or even to acquire another one.
If you breed your own or acquire large quantities of live mice, rats or rabbits, you can set up a mini-gas chamber to quickly euthanize the prey. By 'charging' a deep enclosure, such as a tall aquarium or a clean garbage can, with carbon dioxide (CO2), and then placing the prey inside, they are killed almost instantaneously, being rendered unconscious when they hit the gas. (Note: you cannot euthanize reptiles or amphibians this way as their oxygen metabolism is very different and they can live surprising long periods of time in an oxygen deficient atmosphere.) Gassed prey should be frozen for several weeks before feeding out. This will dissipate any gas in the tissues (which some people feel may be harmful based on experience with birds of prey freshly gassed rodents) and will kill any parasites in the rodents.
Defrosting Frozen Prey
First off, you don't feed out the prey while it is frozen! You do need to thaw it thoroughly and warm it slightly before feeding it out.
Freezing for 30 days kills off most parasites and other organisms that may be harmful to your herp. Prey may be kept safely frozen and fed out for up to six months after the date it was first frozen.
Remove the number of prey items you need from the bag of prey. You can place them in a clean plastic bag and soak in warm water, or leave in the refrigerator overnight to defrost, warming up in warm water. If you are skilled with your microwave, larger prey may be defrosted and gently heated using the defrost setting or lower power settings. Small pinkies can be quickly defrosted and warmed by holding under warm running water, or in a bag on top of a warm surface, such as the stove-top over the pilot light.
Always make sure that not only is the frozen prey thoroughly defrosted but that it is warmed up to a temperature above room temperature. You do not want your warm reptile eating cold prey, and warming the prey also makes it smell more strongly, and thus more attractive, to your reptile, and may be especially important when feeding reluctant feeders and when in the process of converting live feeders to killed.
Feeding Killed Prey
When first converting your herp from live to killed, try first offering a killed prey by dangling it from hemostats or kitchen tongs -- never hold the prey in your fingers! You may need to move it back and forth a bit to catch the herp's attention. Be prepared for the strike and quickly release the prey.
Converting Live Feeders to Eating Killed
If the herp is not interested, you might need to first feed a small stunned live prey, followed immediately by a freshly killed prey, then a prekilled prey. At the next feeding, start off with a freshly killed prey, followed immediately by a prekilled prey. When these are easily taken, go to offering the prekilled prey.
Converting Non-Rodent Eaters to Rodent Prey
Some snakes available in the pet trade are amphibian and lizard eaters. This makes it not only difficult to obtain prey for them, but makes it rather difficult to convert them to eating rodent prey.
A suitable food such as a frog or lizard should be obtained and humanely euthanized for feeding. Instead of feeding it out, however, the lizard or frog should be rubbed all over a suitably sized prekilled mouse or rat to scent it. The scented rodent is then offered for feeding.
Another method is to pith (stick a pin or small nail) into the brain case of a killed rodent; this intensifies the scent and may attract a reluctant feeder into feeding.
For other suggestions on how convert to feeding killed rodents or to get reluctant feeders feeding, contact your local herpetological society.
For information on euthanizing reptiles, please see Stephen Barten DVM's article on euthanasia and my note on the inappropriateness of decapitation as a method of euthanization of reptiles. Also available are excerpts from reptile care texts on feeding prekilled, Reptile Veterinarians and Curators on Feeding Rodent Prey, with some photos of chewed-up snakes.
You may, or may not, have heard that Ball Pythons can be finicky eaters. This is somewhat true. Wild caught adults are generally by far the more frustrating feeders. Captive hatched and captive bred snakes seem to adjust better to captivity and are better about eating on a regular basis. The process of feeding occurs in a few steps. First the snake identifies prey by the scent, color, size, movement, and temperature. If the Ball Python feels that it's in a safe location and won't be molested during the eating process, it will bite and coil around the intended prey item. The coil is intended to kill the prey by suffocation. After the prey stops moving, the snake then usually finds the head and begins the process of swallowing. After the food is in it's stomach, the snake will want to find a small, dark, and warm location to lay around for four or five days and digest the food. In the wild, this warm and dark location is usually a rodent burrow, after the snake has eaten the inhabitants.
So how often should you offer food to your snake? Well that depends on a few factors, notably the age of the snake. Younger snakes (16-30 inches) that are still growing fast will need more food. Older snakes (30-48 inches) won't need to feed as often. I feed my young snakes once every 7-10 days. They are capable of eating small to average size mice as hatchlings. Adults can pretty easily eat a rat that measures five or six inches from nose to butt. I feed my adult males about every three weeks, and the adult (breeding) females eat about once every two weeks. Snakes eat whole animals and do not need vitamin supplements, although you may want to add a little calcium to a gravid (pregnant) female's diet to help in egg production. This feeding schedule assumes that the adults will be off feed for a few months during the winter/breeding season. You may find other information on Ball Pythons that suggest feeding more often, but I believe that most people over feed their snakes. Snakes in the wild never have the opportunity to become obese due to less food availability, and more activity hunting for it.
Should you be offering live or dead food? It generally depends on the individual snake, but I offer prekilled food items. Dead food can't fight back, and I can kill the rodent quicker (less pain for the animal) than a snake does. If the snake has gone awhile without food, is looking thin, and I've exhausted most other options, live food is something worth a try. The downside to offering live food is that the rodent will fight back and can harm your snake. Do NOT leave a live rodent in a cage with a snake unattended! If the rodent attacks your snake, it will scar it, and possibly deter the snake from eating. This photo shows some scarring which is typical of prey items bites/attacks. I have enough of a need for rodents, that I get them frozen by mail order. After a few hours of thawing under a heat lamp, most of my snakes readily eat. Most pet stores will prekill a rodent for you if you ask. If it's left up to you, there are a few simple and painless ways to get the job done. The easiest would be to place the rodent into a small paper bag and hit it against a hard stationary object. The rodent impacts with enough force to instantly kill it. The other option, is to hold the rodent by the tail. Using a ruler or similar object pin it to a table top at the base of the skull. With a quick pull of the tail up from the table, you break it's back and separate the spinal column, thus killing the rodent. In my opinion, either of these two methods are the best way to accomplish this uncomfortable task.
What type of prey item should you offer to your Ball Python? Ideally your snake will eat either lab mice or rats which are cheap and easy to get. I would strongly caution against feeding your snake wild mice or other animals. There is no way of telling what diseases, parasites, or poisons that a wild mouse is carrying. Gerbils and gerboas are a Ball Python's natural food item. If your snake doesn't happen to like rats or mice, a regular pet store gerbil is pretty tempting, albeit a little more expensive.
What can I do to get this snake to eat?! This is a question that most Ball Python owners have asked themselves at one time or another. The first thing you should do is RELAX. A six or eight month fasting period is not unheard of, nor in most cases will it harm your snake. I would suggest getting a postal scale and monitor any weight loss. If your snake doesn't loose much more than about 15-20% of it's original weight you shouldn't worry. Stress is usually the reason that Ball Pythons don't eat. Your Ball Python can be feeling stress: from not being comfortable in it's (new) home, from parasites (either internal or external), from you handling the snake too much, or from infections (respiratory, mouth rot, blister disease, etc). Assuming that the snake is otherwise healthy, free of parasites, and just not eating, try some of the following:
Occasionally the snake decides to take a rodent, but it's not the preferred size of meal. A small mouse is but a snack for an adult Ball Python. Sometimes if you offer a few items, the snake will eat more than one rodent at a sitting. You can also strongly encourage a Ball Python to take a second (or third) rodent during the last stages of swallowing the previous one. As the last of the legs go down, using the hemostats, you can introduce the head of another rodent into the snake's open mouth. Most of the time, the feeding response is strong enough that the snake will just keep swallowing. I use this technique with my adult pythons which usually take gerbils or mice. You can get them to swallow a rat after the gerbil/mouse and end up with a good sized meal for the snake.
Notice in the preceding section that I did NOT suggest you try and force feed your snake? I don't think that force feeding is something which should be done. It's stressful on you and the snake. Force feeding is something which was done by a lot of zoos many years ago before the keepers knew exactly what the care requirements were for snakes. They would force food and/or a liquid diet down a snake's gullet by use of a rubber hose or broom handle in some cases. This does not solve any problems and creates a lot more. The slight exception that I have to that rule is "Assist Feeding" of hatchlings. I do NOT suggest trying this on adults! Sometimes hatchlings don't eat right way. After six weeks of trying or so, I have done what I call assist feeding. Grab a small dead mouse (aka hopper or fuzzy) with the hemostats just behind the head. Then grab the hatchling Ball Python just behind the head with your thumb and forefinger. GENTLY use the nose/face of the rodent to open the snake's mouth. Usually once the mouse's head is in the snake's mouth, a feeding response will kick in and the snake will start to swallow the mouse once you set the snake down. I do NOT force the mouse down the snakes throat! This can cause injury to the snake, and is not advisable. It's been my experience that given time, the right conditions, and patience, Ball Pythons will eventually eat.http://www.kingsnake.com/ballpythonguide/
Before specific snake feeding recommendations are made, it is important to make several points and cautions regarding the feeding of captive snakes. The most respected herpetologists and experienced snake hobbyists all agree that captive snakes should be fed dead or incapacitated prey whenever possible. This is because such prey cannot injure the feeding snake. Providing killed prey that has been frozen is convenient and economical for the hobbyists. Snakes may be induced to eat thawed, frozen prey animals by clipping hair from the coat of a live rat and rolling the proposed food in it just before feeding. Though freezing, thawing and subsequent feeding of whole prey animals is a common practice among hobbyists and herpetologists, some experts believe that such food sources should be "gutted" (eviscerated) before they are frozen. This greatly reduces the possibility of generalized bacterial contamination of the carcass. To replace those nutrients within the viscera that would otherwise be lost, the hobbyist can place a gelatin capsule filled with a vitamin/mineral/amino acid supplement (Nekton-Rep: Nekton Products, W. Germany) into the body cavity before feeding the thawed prey animal to the snake.
Rodents (rats and mice in particular) left unattended and unobserved within an enclosure with a supposedly hungry snake sometimes turn on the "diner" and inflict serious bite wounds on it. These "dinner becomes the diner" incidents are most likely to occur when a snake is ill or otherwise uninterested in feeding. If snakes do not accept freshly killed or well thawed frozen prey, the live prey must be stunned so that it is sufficiently incapacitated and unable to injure the snake. Live rodents can be placed in a paper bag, which is then swiftly slammed down on a countertop to stun the rodent inside. If such an incapacitated animal is offered to a snake that is generally accustomed to receiving its food in this fashion and the snake refuses it, the prey animal can be killed and frozen, and offered at a later time. If it is not possible to offer anything other than live and fully conscious prey for a snake to successfully feed, the encounter must be carefully supervised. If a snake shows no interest in feeding within 10-15 minutes after the prey has been introduced, the prey should be removed and all of the possible reasons for the snake's lack of interest in feeding should be investigated. (See section on Failure to Voluntarily Feed). If other similar attempts to feed the snake within the next 1-2 weeks are equally unsuccessful, veterinary help should be sought at once.
Infections: Snakes acquire a large number of infectious agents from the foods they consume, especially because of the snake's habit of feeding on whole prey items. It is not practical or possible to ensure that all prey animals are absolutely free of disease-causing agents. However, prey animals that are to be fed to captive snakes should appear healthy and come from a reliable source. Extreme caution should be exercised when feeding snakes. This is especially important if a given snake is expected to be hungry and if human-snake interaction is limited to feeding times. An overzealous and hungry snake is very likely to strike at a person immediately after the enclosure is opened and as the prey item in introduced. Large snakes can be especially treacherous and dangerous at these times because of their ability to overcome and overpower their keepers. Hobbyists and even a few expert herpetologists have been seriously injured or even killed at such times.
Great caution must also be exercised when feeding more than one snake within an enclosure. Serious problems result when 2 snakes choose to prey on the same food item. If one snake attaches to the front of a mouse and another attacks at the tail end of the same mouse, neither snake will surrender its hold. Both snakes will continue to feed and eventually one will consume the other! When 2 or more snakes are housed within the same enclosure, they should be fed individually by holding the prey animal in long forceps or tongs.
Captive snakes as a group usually do not suffer from major nutritional deficiencies, unlike the majority of reptiles kept in captivity. This is largely because pet snakes are allowed to feed as they do in the wild, on whole prey items. The prey species fed to captive snakes are undoubtedly different from those present in the snake's natural environment. Further, the relatively narrow diversity of prey animals that can be fed to captive snakes due to practical and economic considerations is in contrast to the wide variety of prey animals potentially available to wild-living snakes. In spite of these major differences, the incidence of malnutrition and malnutrition-related problems among captive snakes is quite low; markedly contrasting the usual situate with most captive reptiles and their seemingly limitless malnutrition-related disease problems. The potential for malnutrition and malnutrition-related disease tends to be greatest among juvenile snakes fed primarily very immature vertebrate (rodents, birds, reptiles, amphibians, etc.) and invertebrate prey species (insects primarily). These food items are not as nutrient-rich as their more adult counterparts.
Feeding schedules for captive snakes vary with the age, species, size, condition and specific requirements of the individual. Generally speaking, pet snakes are usually fed once every 1-2 weeks. Juveniles and adults for which a relatively rapid growth rate is desired can be fed more frequently, providing that environmental temperatures are warm enough to allow complete and thorough digestion. Older snakes are usually fed less frequently, often once every 3-6 weeks. The number of prey animals offered at each feeding is determined by the same factors discussed above with regard to frequency of feeding. Overfeeding must be avoided because of the risk of obesity. Too-frequent feedings and allowing a captive snake to consume multiple prey animals at each feeding encourages rapid growth. It also leads to obesity in older animals. The relative difficulty in procuring food limits this phenomenon in the wild.
Article by Melissa KaplanFirst Things First
The most common environmental problem is wrong temperatures, either too hot or too cold.
If you don't use a thermometer, use one. If you have a thermometer and it says that the temperatures are where they are supposed to be, get another thermometer and double check. Sometimes thermometers fail, or are less than accurate to begin with. If you have the self-adhesive type of thermometer commonly sold for reptiles, and have peeled it off and re-glued it to another place, that can destroy its accuracy. Heat-sensing "guns" can be used to check the heat at places difficult to place a thermometer, such as on a branch used for basking by an arboreal reptile, or rocky perch used by a desert lizard.
All of this assumes that you already know what the proper temperature gradients, and basking temperatures, are for your reptile. If you don't, find it out! Every species has different requirements. While they can be loosely grouped by habitat type (woodland, desert, wet tropical forest, temperate riparian, etc.), where they live in that habitat can affect temperature requirements, as can their lifestyle (nocturnal or diurnal). If you can't find species-specific information for that rare swift you have, research the requirements known for other species of swift and other lizards that live in the same places as they do, and compare what is known about yours (habitat type, lifestyle, habits, etc.) to what the known species require.
You need to provide heat in a way that is similar to how the reptile obtains and uses heat in its environment. Very few reptiles actually bask on hot rocks in the wild, so, despite the advertising of such products, hot rocks are appropriate for very few species of snakes and lizards, and not at all for chelonians. There is more information on the various products used for lighting and heating in the Lighting and Heating article.
Humidity is an important environmental - and health - factor.
If the environment is too dry, based on the species requirements, it will cause dehydration in the reptile. Dehydrated animals will reduce their food intake until they simply stop feeding. Forcing them to eat will only worsen the dehydration as the gut pulls fluids out of cells to try to get the food digested. Serious, even fatal, hypovolemic shock thus can be induced.
Information on rehydrating reptile can be found in the Fluid and Fluid Therapy article. Ways to increase the humidity levels in the enclosure or environment itself can be found in the Microclimate article.
Lizards and most chelonians require ultraviolet B (UVB) wavelengths in order to manufacture their own vitamin D3, which is a critical part of the calcium metabolization process. This is especially critical for herbivores or largely herbivorous reptiles, as well as diurnal insectivores.
The only safe ways to provide UVB for your reptiles is by giving them access to direct sunlight (not filtered through regular window glass or reptile/aquarium tank glass, or plastic) or by using a UVB-producing fluorescent light made for this purpose for reptiles.
Plant and aquarium lights do not produce the UV wavelengths reptiles need to produce D3.
"Full-spectrum" lights may emit the full visible spectrum (many don't as they are "color corrected" to affect the colors you see, which affect the way your reptile's colors appears to you and your reptile's environment appears to the reptile), but they do not - cannot - produce UV.
UVB-producing fluorescents must be properly installed (no more than 18" from the reptile) and replaced at least annually. While there are several lights made for this purpose, not all produce enough UVB. See the articles on UV lighting at the Captivity page for more information.
Metal halide and mercury vapor lights are sometimes recommended for use with reptiles, promoted by the fact that they provide both heat and UV. Unfortunately, they provide such high levels of UV that they pose a health threat to both the reptiles and the humans who keep them. Some of these issues are discussed in the article on Mercury Vapor products . Another thing to keep in mind is that, in the past, many of the people who use these types of lights kept them on for only a few minutes, or up to half an hour or so, a day. This may reduce the level of harmful radiation the reptile and keeper are exposed to, but it creates health problems and stress in the reptiles if they are not provided with other forms of heating and lighting for the rest of the day light hours to provide the thermal gradients and photoperiods they require..and at that point, you haven't saved any space, time, or money by using such a combination heat/UV product because you still have to use other heating and lighting sources.
The reptile's habits need to be provided for in an enclosure large enough to provide for all their needs (basking, lounging, feeding, sleeping, places for food and water, furnishings, and open space for moving around). For example, arboreal reptiles furnished with climbing apparatus, burrowing reptiles with something to burrow in, all reptiles provided with places to hide. More information on this can be found in Reptile Housing: Size, Dimension and Lifestyle.
More information on identifying problems related to improper environment - physical and social - can be found in the Signs of Illness & Stress article.
All prey is not created equal. At the very least, there is the difference between vertebrate and invertebrate prey.
Fish, amphibians, reptiles, birds, and mammals are all included in the diets of the many carnivorous and omnivorous reptilian species. Some are generalists, feeding on many different types of prey, while others are specialists, feeding on a limited number of species of prey. Most reptiles feed in the wild only on living prey, though a few species are carrion eaters.
Research into the nutrient content of different prey animals indicates that there is little difference between them nutritionally when considering healthy, properly fed prey species. Thus, from a nutritional standpoint, converting a reptile from feeding upon one type of prey should be acceptable. Unfortunately, the reptile in question may not be so logical about these things, preferring instead to feed on its usual lizards, frogs, or snakes rather than switching to furry mice. Suggestions for scenting one prey with another are discussed in the Hatchling Snakes article; they should work equally well for carnivorous lizards
The size of prey fed to a reptile bears directly on the reptile's ability to catch, swallow and digest the prey. A rule of thumb for lizards is that the prey should be no larger than 2/3 the length of the reptile's head. For snakes, the rule is that prey be no wider at its widest point than the widest part of the snake's body. Feeding prey that is too large may result in regurgitation, injuries from swallowing and regurgitation, seizures, partial paralysis, gut impactions, even death.
One way to attempt to convert a non-rodent eater to feed on rodents is to scent the rodent with the reptile's preferred prey. A living or defrosted frozen lizard or frog (or other preferred food item) may be kept on hand to rub against the killed rodent just before offering it for feeding. This will transfer the scent of the preferred prey to the fur or skin of the rodent. Dangling the rodent from a pair of tongs or hemostats will create the illusion of movement. Combined with the scent, this may entice and trick the reptile into feeding.
The reasons for feeding prekilled rodent prey are discussed at length in the Feeding Prekilled Prey article, as are tips for converting live feeders to prekilled. Many reptiles become frightened of live prey, especially if they have been bitten before. With young snakes or lizards, the live prey may just be too active for them. Feeding prekilled eliminates both the fear and the risk of injury.
Do not leave invertebrate prey, especially mealworms, kingworms, or crickets, in the enclosure with a reptile without also leaving food for the prey. If the reptile does not eat the invertebrates right away, they will soon get hungry and start feeding on whatever is available, which is usually the reptile. Many reptiles become so severely chewed up and stressed out by their prey that they require veterinary care; such reptiles, like snakes who have been attacked by rodents, can be very difficult to get self-feeding again. Another scenting trick is pithing. This involves piercing the braincase of the killed prey with a pin or nail before offering it to the reptile. Never leave live rodents in an enclosure with the reptile. Too many big boids have died or been permanently disfigured by rodent attacks.
Something to try before pithing, however, is dipping the prekilled prey into some warm chicken broth. This is especially effective in species whose wild diet includes birds. Canned chicken broth may be poured into ice cube trays and frozen, defrosting cubes as needed. Depending on the size and number of prey you need to dip at each feeding, you can use the trays for regular sized cubes or trays for miniature cubes. (Prominent snake breeders Dave and Tracy Barker discovered the efficacy of chicken broth.)
Some reptiles are sensitive to color, and have definite preferences for prey of certain colors. With rodents, this may mean brown or parti-colored mice rather than white mice (after all, there aren't a lot of white or albino mice in the wild, as they tend to not survive long enough to pass on their color genes). This color preference may extend to insect-eaters as well. Adding powdered spirulina or alfalfa to the food-and-vitamin mix fed to crickets will turn them green, making them more acceptable to reptiles who typically eat green insects in the wild. (Chameleon keeper Alon Coppens discovered this when he ran out of naturally green insects for his picky Nosy Be C. pardalis.)
Care must be taken not only in the type and size of food selected for feeding, but in the presentation of the food as well. Proper presentation not only makes food attractive to the reptile, which will help stimulate feeding, but will ensure that the food can be safely consumed.
A plate of some sort must be used when the reptile is kept on a substrate of soil, shavings or other particulate matter. This will prevent the unnecessary uptake and accidental ingestion of the substrate itself. While there is nothing to prevent this from occurring in the wild, captivity is not the wild. We are still ignorant about what factors or organisms that may prevent impactions in the wild that are missing in the captive environment.
An alternative is to remove the reptile from its enclosure and place it in a special enclosure reserved for feeding. Separate feeding enclosures will be required when two or more snakes are housed together. Keeping and feeding them in the same enclosure may well result in fewer snakes as one snake eats the other merely because it smells like prey, or when both have tried to eat the same prey animal. Separation may also be required when housing two or more lizards or chelonians together when one of them is unable to compete successfully with the others for access to enough food.
Plant foods should be thoroughly mixed together to prevent the reptile from picking out only certain plants and leaving the rest. Captive diets consisting of just one or two plants is not nutritious and will result in nutritional deficiency disorders.
Rodents/Birds/Reptiles/Amphibians: Using a forceps (hemostats) or kitchen tongs, grasp the prey by the base of the tail and dangle it for the reptile. You may find that "walking" it around a bit will better simulate the movement of a live prey animal and thus better trigger a feeding strike.
Fish: Let the fish swim in the water bowl or special feeding bowl, large enough for the aquatic turtle, or semi-aquatic lizard, snake or turtle to get into and swim to catch its prey.
Worms/Larvae: Individual worms or larva may be held in forceps to introduce the prey to the reptile. A meal's worth of worms or larvae may be placed in a shallow bowl or saucer, enabling the reptile to get in but preventing the worms from escaping. Leave some of the food being fed to the worms in the bowl so that they have something to feed on if they are themselves not eaten right away.
Crickets: Crickets may be set loose in the enclosure for most reptiles. For turtles, they may need to be held with forceps. On a daily basis, check under furnishings, branches, and potted plants to get the crickets who have hidden back out into the open again. Put some of the food being fed to the crickets in their own enclosure into the reptile's enclosure so that the crickets have something to feed on if they themselves are not eaten right away. A piece of fruit placed in a jar lid will provide the crickets with an easily accessible source of moisture. A rock should be placed in the reptile's water bowl so that if crickets jump into the water they will be able to climb out onto the rock and jump free and thus escape drowning.
Terrestrial feeders: The plant food may be placed in a shallow bowl, jar lid, or saucer. Offer vertebrate prey as indicated above. Worms, larvae, and killed vertebrate prey may be placed on top of the plant food, mixed into it, or offered separately.
Aquatic feeders: The leafy greens may be floated on the water. If turtle food sticks or pellets are being offered to aquatic turtles, they may be floated on the water as well.
When the food is offered will also affect feeding and metabolism. Failure to proffer the right food at the right time, and in the right way, may well result in malnutrition or starvation.
Some species feed at night. Others will easily take food around sunset but will not feed during daylight hours. Still others will only eat during the day. Offering food outside the optimal feeding times for the species may result in reduced intake or failure to feed.
Some reptiles may be unwilling to feed when they are being watched by other animals, including humans. Still others will compete so fiercely with other cagemates for food that injuries may occur or the cagemates may themselves become reluctant to feed and so slowly starve to death. Thus, observation of captive species must be done carefully so as not to stress, or alter the behavior of, the animals being watched.
Feeding frequency may also lead to nutritional problems. Some hatchling lizards and small adult lizards need to feed several times a day. Other lizards may feed comfortably once a day or once every other day. The feeding frequency may change throughout the year due to breeding season or coinciding with natural cycles found in the animal's native habitat, such as the dry or wet seasons, cool winters, hot summers, or breeding season.
Wash your hands with hot, soapy water, rinse thoroughly, and finish off with cold water. This will remove the scent of other animals - predator and prey - from your hands and give your hands a cooler thermal signature than the prey you are offering (by tongs or forceps, please) to reptiles who use heat sensing to locate prey.
There are no cut-and-dried rules on feeding reptiles. Each species will have its own requirements. Feeding amounts and frequency are based as much on the reptile's evolved dietary needs and metabolic size as it is on its being maintained in a proper environment.
Generally speaking, smaller reptiles need to eat more frequently than larger reptiles; younger reptiles more often than older ones; insectivores more frequently than vertebrate eaters; and herbivores more frequently than omnivores or carnivores. Most young lizards and herbivorous reptiles will need to eat every day, whereas young snakes may eat twice a week. Sick reptiles, or those preparing for breeding, may need to eat more or more often than healthy adult reptiles not in breeding season. Reptiles tend to eat more during the seasons that coincide with the highest food availability in their native habitat (generally corresponding to our spring and summer months) than during the cold or dry seasons.
A reptile who acts hungry probably is. "Acting hungry" may include such behaviors as instantly coming alert, head raised, and, in snakes and some lizards, active tongue flicking, when the caretaker approaches the enclosure. Caretakers being struck or bitten by an otherwise tame and calm snake or lizard when they put their hands in or near the enclosure is another sure sign. Except for certain gorge feeders (such as savannah monitors and Burmese pythons), a reptile maintained in a proper environment, who gets plenty of exercise, and is fed a healthy diet, is difficult to overfeed. If they are not hungry, they will not eat.
Commercial reptile foods (dried, broth-flavored insects, "sausages", frozen, canned and dried foods) sound like the perfect answer to what to feed your lizard, snake or chelonian. The only problem is that, despite packaging, advertising, and pet store claims, except for some of the aquatic turtle foods, these food products were not longitudinally tested and many are proving to be less nutritionally "complete" and "balanced" as claimed. Reptile keepers and veterinarians are finding that animals maintained on many of these foods exhibit developmental abnormalities (growing too fast or too slow) and nutritional deficiencies such as metabolic bone disease. It is best to not consider these as suitable substitutes for whole prey or fresh plant diets. For more information, see the Evaluating Commercial Diets and related articles in the Food & Feeding page..
Feeding baby snakes may present some unique problems. Captive bred snakes remain genetically programmed to recognize certain scents and shapes as being "food." When those shapes and smells don't materialize, they may be reluctant to feed.
Most baby snakes do not feed for the first several weeks after hatching as they are still living off the remains of their yolk which is retained inside their bodies; this takes about 10-20 days. In the wild this time would be spent finding water, basking, sleeping, and hiding spots, and generally learning about its environment. Only after the first shed or two, anywhere from 2-4 weeks after hatching/birth, will they start looking for food.
In captivity, they may often be started on rodent prey, specifically pinky mice, causing them to imprint on the prey and so become willing feeders on at least that species of rodent for the duration of its life.
Methods to help them start feeding on proffered food items, besides ensuring they have a properly set up and furnished environment, are discussed above and in the articles referenced below.
Aquatic turtle hatchlings will often begin to feed in small containers, with water deep enough for them to swim and dive and equipped with a haul-out place. Wriggling insects, such as pinhead crickets, moving on the surface of the water will attract the hatchlings' attention and stimulate the feeding response. Once they are feeding easily and heartily, they can be fed in their regular enclosure. If feeding many hatchlings, care must be taken to not overcrowd the feeding enclosures. If they are being fed in their regular enclosure, some should be removed to one or more separate feeding enclosures. Care must be taken to watch them carefully to see if any are not able to compete successfully for the food.
Terrestrial turtles are omnivorous. A selection of finely chopped or shredded plant food can be placed in a feeding container or in a substrate-free area of their enclosure. The prey arthropods may be mixed in with the plant matter or placed on top of it. Mixing the prey with the plant matter is a good way to get them started eating the plant matter.
Tortoises are grazers and should be offered a variety of vegetables and leafy greens as well as drier roughage for foraging. The chopped vegetable and leafy greens should be set out on a jar lid or other flat surface, enabling the small tortoises to easily climb on and forage in the midst of the food. They may be kept on a mixed bedding of alfalfa and timothy hays. This will give them traction to walk on (unlike alfalfa pellets), and is easily moved about so that it may be burrowed under. Since tortoises will try to eat everything, no wood, paper, gravel, or other substrates should be used, nor should Styrofoam-type plates be used to as a feeding plate.
Carnivorous lizards should be separated at meal time to reduce aggressive competition for food. Depending upon the individual lizard's prowess, some may need to be placed in smaller containers to restrict the movement of their prey. Insectivores should be offered a variety of prey items to maximize nutrient intake.
Herbivorous lizards may also need to be separated to reduce feeding competition. As with neonate tortoises, shallow serving platters should be used to enable easy access and foraging in the food.
Omnivorous lizards may need to be separated for feeding if they are not able to compete successfully with cagemates. They may be fed in a manner similar to omnivorous box turtles, with their animal prey mixed into their plant matter. In addition, crickets should be offered to them either in their enclosure or in smaller feeding containers to ensure they are able to catch them.
When All Else Fails
If your reptile has non-feeding long enough so that it starts to visibly lose weight/mass, you need to get your reptile checked by a reptile veterinarian. Just because they can go a long time without feeding doesn't meant they should. While there is nothing to worry about if your hatchling doesn't feed until after its first or second shed, or your adult isn't eating during breeding season, or your carnivore of any age isn't interested in food during pre-shed and shedding, an apparently healthy reptile whose environmental needs are being met and who is being offered appropriate prey in the appropriate way but who still won't eat has a problem. Systemic infections, heavy loads of internal parasites, boid inclusion body disease, congenital deformities, gut obstructions, and more can cause inappetance or inability to feed.
If force-feeding is necessary, don't shove a whole prey down its throat. That is highly stressful (for you and the reptile) and may end up burning more calories than you are shoving in. More information on force-feeding can be found in the Emaciation (Starvation) Protocol article.