Frogs are amphibians, a word of Greek origin that means two lives. Most adult frogs live in damp places in woods near streams or ponds. But when mating season comes, usually in the spring, they migrate to ponds, wetlands, and seasonal pools to lay their eggs. The eggs hatch into tadpoles, a completely aquatic stage that breathes with gills and eats algae. Depending on the species, the remain in the tadpole stage for as long as a year before they develop legs and lungs and move onto land as adults.

Eggs, tadpoles and adult frogs are a crucial component of many ecological communities. A vital link in the food chain, they serve as food for aquatic insects, fish, mammals and birds. But carnivorous adult frogs do their share of eating too, feeding on mosquitoes, flies and aquatic invertebrates. Some frogs even eat small fish, amphibians, reptiles birds and rodents. One recent study found that a healthy frog population was removing over 50,000 insects per acre per year from one area under study.