A mammal is a class of warm-blooded vertebrates that possess characteristics such as hair or fur, mammary glands for nursing young, and three middle ear bones. They are distinguished by their ability to regulate body temperature and typically give live birth (with few exceptions). Mammals can be found in various habitats and exhibit diverse adaptations, contributing significantly to ecological systems. Examples include humans, whales, and bats. The study and classification of mammals fall under the field of zoology.