Mammals are warm-blooded vertebrates distinguished by features such as hair or fur, mammary glands, and a neocortex in the brain. Examples include humans, dogs, whales, and bats. Most mammals give birth to live young, and females typically nurse their offspring with milk produced by mammary glands. Mammals exhibit a wide range of adaptations, from the specialized limbs of bats for flight to the streamlined bodies of dolphins for aquatic life. With diverse habitats, mammals play vital roles in ecosystems, functioning as predators, herbivores, and contributing to ecological balance. The ability to regulate internal body temperature and the presence of hair or fur are key characteristics that define this class of animals.