Mammalian is an adjective used to describe animals that are warm-blooded, have fur or hair, and feed their young with milk from mammary glands. Warm-blooded is an 11 letter term that describes animals that maintain a constant body temperature regardless of the environment. This is in contrast to cold-blooded animals, which rely on external sources to regulate their body temperature. Mammals are found in all parts of the world and include species such as cats, dogs, horses, and humans.