Some amphibians are ectothermic, meaning they rely on external sources of heat to regulate their body temperature. This includes frogs and toads, which are both members of the Anura order. Frogs, which have four letters in their name, are found in a variety of habitats and can be found on every continent except Antarctica. Toads, which have five letters in their name, are usually found in moist environments and are characterized by their dry, bumpy skin.