A female bullfrog may lay up to 25,000 small eggs that are held together at the surface of the water. Bullfrogs have teeth in the roof of their mouth and a muscular tongue capable of flipping prey into their mouth. Bullfrogs may remain at the tadpole stage for up to 2 years. A longer tadpole stage means a larger frog after metamorphosis which usually means a better chance of survival. Hearing is one of the most important senses to a frog.
Bullfrogs close their nostrils and continue to breathe through their skin while under water.
Ecology and Conservation Where bullfrogs occur naturally, they are common and help keep populations of insects, such as mosquitoes, in check. But they have been introduced into areas of the western United States where, because of their appetite, they are capable of reducing or destroying local populations of native species. Their populations can increase to become out of balance with the species native to those habitats because often they have no natural predators and their toxic skin secretions make them unpalatable to many animals. Because bullfrogs, like all amphibians, have porous skin and respond quickly to changes in the external environment, the health of their populations can be an indicator of the health of the environment. Bibliography Beringer and Johnson.