During their last few months as tadpoles, the hindlegs grow steadily, the broad fin-like tail is absorbed, the front legs break out through the gill chamber, and they begin to breathe air. They are then little frogs about 2 inches long with broad gaping mouths adapted to catching and swallowing crayfish, snails, water insects, and smaller frogs and toads. As adults they may also devour small turtles, snakes, birds and mice. After another 2 years they are 4 to 5 inches long and begin to breed. They have been known to live 15 years in captivity.
Bullfrogs have a host of enemies.
Little tadpoles are preyed upon by water beetles, water bugs and fish. Larger tadpoles and adults are eaten by larger fish, water snakes, herons and other water birds, snapping turtles, raccoons, mink, skunks and owls, but man is their worst enemy. Schools use a half-million bullfrogs annually in biology courses. As a result, most states have closed seasons and other restrictions on bullfrog hunting. Try sitting quietly for at least a half-hour near a pond or marsh.