Of the 3,260 species of amphibians currently recognized in the world, there are approximately 2,770 species of toads and frogs. The largest species is the Goliath frog, Rana Goliath of the west coast of africa which may have a body length of nearly 14 inches and may weigh as much as five pounds. One of the world's smallest frogs is Sminthillus limbalus which has no common name and lives in the tropical forests of cuba. It is only a half-inch long. This frog is so tiny that females of the species are able to produce only one egg during the breeding season.
Toads have dry, warty skin, while frogs have smooth, wet kin.
Toads have shorter hind legs than most frogs. Toads hop, frogs jump. Although most people would be hard-pressed to identify a variety of toads and frogs by the sounds they make, people generally are aware of the fact that these animals have voices and are interesting to listen to. When calling, a toad or frog will close its mouth and nasal openings and force air from its lungs over the vocal cords into the mouth cavity, then back over the vocal cords and into the lungs. These animals use an enlarged throat or expandable vocal sac to resonate their calls.