Mammals are one of the classes of animals.
Scientists have classified, or divided, all animals into groupings according to the ways in which they are alike.
All mammals have one characteristic that no other animal have, mammals are the only animals whose females produce milk to feed their young. The word mammal comes from the Latin word mamma, which means “breast.”
Other characteristics distinguish mammals from most other classes of animals.
Mammals give birth to live young; they have a backbone; they are warm-blooded; they have a well-developed brain; they breathe air; and their bodies are covered with hair.
There are many different kinds of mammals, but they all have these characteristics. Human beings are mammals. And so are whales, lions, cows, kangaroos, dogs, gorillas, hippopotamuses, armadillos, dolphins, aardvarks, elephants, and bats.
Would you believe, there are fewer kinds of mammals than any other class, only 4,000 in all, as compared to insects, which are divided into 800,000 classes.