The first frogs appeared on earth about 180 million years ago. About 3,800 species of frogs and toads have developed from these early ancestors. Some species spend their entire life in or near water. Others live mainly on land and come to the water only to mate. Still other species never enter the water, not even to mate.
Many kinds are climbers that dwell in trees.
Others are burrowers that live underground. Throughout history, frogs have been the source of superstitions. One old myth says that frogs fall from the sky during a rain. Actually, many species that live underground leave their burrows during or after a rain at the start of the mating season. Because people seldom see these frogs the rest of the year, they imagine the animals fell from the sky with the rain.