In captivity, pet bullfrogs are given crickets, worms, small fish, rodents, and fruit flies. In the wild they like to eat crayfish, water beetles, snails, and dragon fly larvae. Bullfrogs may eat each other, this makes up of 80% of their diet. In a 1935 study, it was found that smaller bullfrogs eat mostly insects. However, larger bullfrogs eat crayfish, frogs and mice. In an Arizona study in 1988, it was found that bullfrogs there eat invertebrates such as snails and insects. While two other studies, one in 1977 (in New Mexico) and the other in 1993 (in New York), found that bullfrogs in New York eat mostly "Ranidae" frogs. The study from New Mexico, found that bullfrogs there eat mostly toads. Adults can help decrease the mosquito population by eating most of their larvae.