What is the Difference Between Warm-Blooded and Cold-Blooded Animals?
“Cold-blooded” animals (ectotherms) have their body temperature regulated by interactions with the environment, while “warm-blooded” (endothermic) animals have an internal temperature kept constant by homeostatic (stability-ensuring) mechanisms. The terms “cold-blooded” and “warm-blooded” are being phased out as they are misleading — “cold-blooded” animals don’t have blood that is necessarily cold, it just varies in temperature based on the outside. Another name for ectotherms are “poikilotherms,” which means animals with varying body temperature. “Cold-blooded” animals are in the majority, and include all invertebrates, reptiles, and everything besides mammals and birds, the only two groups of animals that are warm-blooded. However, part of the reason that the “warm-blooded” and “cold-blooded” terms are no longer scientifically acceptable is that there is no clear-cut distinction, and animals actually fall on a continuum from totally environmentally-regulated temperature to internally
