Their booming bass call is heard from mid-June to July, although last year's tadpoles may emerge a month or two earlier. Males move out from shore and settle among the water lilies to call females. Spawning takes place soon after the females are grasped by males. She extrudes her eggs in a huge, film-like mass on the surface among the water lilies. Bullfrogs produce as many as 20,000 eggs each year.
Tadpoles hibernate in the deep silt of the lake bottom.
The Bullfrog season is short. By early September most are hibernating in muddy pond bottoms. The Bullfrog menu includes birds, other frogs, fish, even their own tadpoles, as well as the usual insects. When held by the hind legs, Bullfrogs may let out a startling scream or squeal.