Feeding is the one area where keeping reptiles may be quite different to keeping other pets. Unlike dogs, cats, rodents and birds, it is difficult to maintain nutritional balance and health by feeding your reptile on commercial reptile foods. This means that you may have to spend significant amounts of time sourcing and preparing “prey” food suitable for your particular reptile species.
What to Feed?
Reptiles will feed on a whole host of prey types, from mammal to bird, fish to amphibians and even other reptiles. It is essential that you thoroughly research your chosen species and understand its natural feeding habits and chosen prey in the wild. Note, however, that for many captive-bred species, it is possible to convert them to feeding on a more convenient prey (e.g. rodents) even if their natural diet is very different. This can be done by rubbing the rodent with the reptile’s natural preferred prey (e.g. a frog) just before offering it; dangling it in front of the reptile using a pair of tongs will simulate prey movement and often trigger the reptile to strike and take the prey.
The size of prey food is quite important as too large a prey may result in injuries from swallowing and regurgitation, partial paralysis, seizures, gut impactions and even death. Generally speaking, prey for lizards should be no bigger than 2/3rds of the lizard’s head while for snakes, it should be no wider than the widest part of the snake’s body.
Colour can be another important factor as some reptiles are sensitive to colour and will only eat prey of certain hues. With rodents, for example, they may prefer the brown or parti-coloured mice often found in the wild over the albino specimens. Many insect-eating reptiles prefer to eat green coloured invertebrates.
Frequency of Feeding
Frequency is just as important as type and size of prey. Again, it is essential to learn your reptile’s natural rhythms in its wild state and to follow that as closely as possible. Some reptiles, for example, feed exclusively at night; others are day feeders; still others will only feed around sunset. Failing to offer food at the right time can even lead to malnutrition and starvation. Remember also that some reptiles are sensitive to being watched while eating while others may become aggressive when competing for food, causing cage-mates to slowly starve to death out of fear of intimidation.
As a general rule of thumb, smaller reptiles will need to eat more frequently than large ones and young reptiles will eat more often than older ones. In addition, insectivores will need to eat more frequently than those eating vertebrates, and herbivore will need to eat more often than omnivores or carnivores. Reptiles that are sick or that are preparing for breeding may also eat more or more often.
Don’t forget also that feeding frequency can change throughout the year, depending on breeding seasons and other natural cycles in the reptile’s place of origin, such as dry or wet seasons.
Live Prey or Pre-Killed?
While it is often believed that reptiles, especially snakes, can only eat live prey, this is not necessarily true and most captive-bred reptiles can be easily converted to feed on pre-killed prey. In fact, in most instances, it is actually better and safer to feed your reptile pre-killed prey. This is because – ironically – the prey can seriously harm your reptile. Many types of prey will put up a vigorous fight when attacked, causing severe injuries such as punctured eyes, cracked jaws, cut tongues and slice wounds on the body.
In addition, some prey, such as rats and invertebrates like meal worms and crickets, can be aggressive feeders themselves, especially if left in the tank with the reptile and with no food or water source of their own. Reptiles that are not hungry tend to ignore prey and will suffer as rats have been known to eat skin and flesh off snakes, while crickets and mealworms will happily gnaw at the skin and suck moisture from the eyes of healthy reptiles.
While some argue that such risks occur in the wild and live prey would be providing a more natural lifestyle, many feel that captive reptiles already lead unnatural lives, without the normal activities and environmental factors of their cousins in the wild – therefore, it is our responsibility as pet owners to keep them from harm. Certainly, reptiles in the wild do get injured in their search for prey but they are usually weakened and will die, following the natural order of things.
While it is possible to learn to humanely kill prey yourself (and always ask an experienced herpetologist to show you how), in many cases, it is easier to purchase a stock of frozen killed prey from a pet store or specialist prey supplier. Make sure that the prey is thoroughly defrosted and warmed up to above room temperature before offering it to your reptile – this will also increase its scent which will tempt reluctant feeders.