They were the first vertebrates to leave water and live on land. Frogs breathe through their lungs and their smooth moist skin. The legs of the frog are used for swimming and jumping. Most frogs can leap twenty to even forty times their own body length. Frogs have sticky pads on their toes to help them grab onto slippery objects.
Frogs start out as unshelled eggs.
After about two weeks from when the eggs were laid, the first tadpoles wriggle out of their eggs. Young tadpoles feed by scraping algae off water weeds. In the next four weeks, the young tadpoles lose their gills, and grow hind legs. Gradually the tadpoles eat more meat, like small water organisms. Twelve weeks after hatching, arms form.