Amphibians do not really have cold blood, but they cannot maintain a constant body temperature like mammals. While amphibians can tolerate and remain active at low temperatures – frogs often arrive in their breeding ponds long before spring spawning takes place – they also enjoy warmth. Frogs often sit at pond edges basking in summer sunshine. Such cold-blooded animals are known as ecototherms; warm-blooded animals like mammals are endotherms.