What is the definition of endothermic animals?

Endothermic animals, sometimes called warm-blooded animals, are those that can generate their own heat to maintain a relatively constant body temperature, regardless of the external temperature. This ability to regulate their body temperature internally is a key adaptation that allows endotherms to be active in a wider range of environments and climates than ectothermic animals (cold-blooded animals), whose body temperature is largely dependent on the surrounding temperature.

Endothermy requires a high metabolic rate, as the animal's body constantly generates heat through cellular processes and muscular activity. To support this high energy expenditure, endothermic animals typically have a fast metabolism and consume large amounts of food relative to their body size. They also have efficient mechanisms for conserving heat, such as insulation (fur, feathers, or fat layers) and the ability to reduce blood flow to certain body parts when necessary.

Endothermic animals include mammals, birds, and some fish, such as tuna and swordfish. They are found in a variety of habitats, from the coldest polar regions to the hottest deserts. Their ability to maintain a stable body temperature allows them to be active at different times of day and night and to survive in environments with fluctuating or extreme temperatures.