Cold-blooded and Warm-blooded Animals
. On land, some invertebrates manage to overcome the problem of cold by using muscles to warm themselves. For example, many large moths and bumblebees use a special form of shivering to raise their body temperature to 35°C (95°F) before they take off, which allows them to fly in cool weather. Bees also maintain warm conditions in their nests, which speeds up the development of their young. But in invertebrates as a whole, temperature regulation is very unusual. In vertebrates, on the other hand, it has developed to a high degree. Vertebrates are customarily divided into cold-blooded and warm-blooded animals, but these labels are not very precise. Biologists normally use the terms ectoderm and endoderm to describe temperature regulation more accurately. An ectoderm is an animal whose temperature is dictated by its surroundings, while an endoderm is one that keeps its body at a constant warm temperature by generating internal heat. Reptiles , amphibians , and fish are ectoderms. Alt...