Most pet frog species thrive on a diet of crickets, cockroaches and other insects. Some of the largest species can consume mice or rats, but it is not necessary to feed them such large prey. While different pet frog species have slightly different dietary preferences, all frogs eat other animals. Typical prey for wild frogs includes insects, arachnids, fish, other frogs and worms.

Ideally, according to About Exotic Pets, pet frogs should be fed a varied diet consisting of several different kinds of acceptable invertebrates, such as mealworms, silkworms, earthworms and moths. However, these foods are not readily available in all markets. Accordingly, it is important to ensure that all feeder bugs are fed a nutritious diet before they are fed to pet frogs. It is also important to dust the feeder insects with a vitamin and mineral supplement on a regular basis to prevent nutritional deficiencies caused by a narrow range of food items.

Some aquatic frogs, such as African clawed frogs, learn to accept commercial food pellets and do not require live prey. Some terrestrial and arboreal frogs, such as dendrobatids, learn to eat prey from their keepers' hands. Because large frogs eat smaller frogs, it is important to avoid grouping differently sized frogs in the same habitat.