The eardrums are very large - those of the males are larger than the eyes. Greenish, light brown to gray on their backs, they have mottled, dark oval spots with light borders and their bellies are cream to white. Males may also have a yellowish throat. Native to the eastern United States, bullfrogs were introduced to California, and most other western states, several times in the past century.
Bullfrogs have strong rear legs with completely webbed feet and are highly aquatic.
They prefer the quiet waters of ponds, streams and irrigation ditches, areas with substantial shoreline cover, where they can hide from predators. Tadpoles feed on algae and small plant materials. Males are territorial and give a challenge call, especially during the day, when another male approaches. Individuals may leave the pond at night or on rainy days and hibernate in the mud in the bottom of the pond in the winter. Some may be active year round in areas with mild winters.