The first frogs appeared about 245 million years ago during the Triassic period. Since this time, frogs have remained relatively unchanged. They are amazingly adaptable and live in a variety of climates.
Frogs are amphibians. Like other amphibians, they are cold blooded and must adapt their internal temperature to that of their surroundings. Some frogs burrow underground or in the mud when temperatures drop to conserve heat. Others, such as the wood frog, use glucose in their blood as a kind of antifreeze, allowing them to survive in a frozen state until the weather warms. Frogs have excellent leaping abilities and are able to extend as much as 20 times their body length.