
Feeding reptiles the proper kinds of prey varies primarily on the type of reptile you have. Fish, amphibians, reptiles, birds, and mammals are all included in the diets of the many carnivorous and omnivorous reptilian species. Insectivorous reptiles feed on mostly insects such as crickets and mealworms. Some are generalists, feeding on many different types of prey, while others are specialists, feeding on a limited number of species of prey.
When feeding reptiles, it is important to recognize its ability to catch, swallow and digest prey which will help you to determine the size and type of prey to select. Providing your reptile with a wide variety of prey presents them with more nutrients and is proven to be more mentally stimulating for them. Some reptiles are afraid of live prey, if this is the case, it may be necessary to feed your reptile pre-killed prey.
Feeding reptiles prey that is too large may result in regurgitation, injuries from swallowing and regurgitation, seizures, partial paralysis, gut impactions, even death. Here is a rule of thumb to keep in mind; for lizards, 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 than the widest part of the snake's body.