Frogs are amphibians, animals that spend part of their lives under water and the remainder on land. They have long, powerful jumping legs and a very short backbone. Most frogs have teeth (in the upper jaws only) but toads do not have any teeth.
Life cycle: Like all amphibians, frogs spend their lives near water because they must return to the water to lay their eggs. Frog eggs are laid in the water. When they hatch into tadpoles, they breathe with gills and swim using a tail. As they mature, they lose their tail, and they develop lungs for breathing air. In harsh climates, frogs bury themselves in sand and mud and hibernate (sleep very deeply) through the cold winter.
Diet: Frogs eat insects, catching them with their long, sticky tongue. They also eat small fish and worms.
Classification and Evolution: Kingdom Animalia (animals), Phylum Chordata, Class Amphibia (amphibians), Order Anura (Frogs and toads). The first true frogs evolved during the early Jurassic period, about 200 million years ago (during the time of the dinosaurs).