There are many groups of animals. Mammals are in one group, called a Class. All mammals share some traits.
Mammals have body hair (except for marine mammals, such as dolphins and whales). A mammal’s hair is important for keeping warm and protection from the sun. Their hair can be adapted as a protective tool, such as the quills on a porcupine or the shield on an armadillo. It can also act as camouflage to blend into the habitat.
Female mammals make milk to feed their young. The milk is full of fat and protein that helps young grow and develop.
Mammals protect their young from predators. They provide a safe home for their newborn young and may teach them, as they grow, how to find food and avoid predators.
Mammals are warm blooded.
They also have a backbone which helps them move quickly and easily.
Mammals have specialized teeth with some teeth for cutting, some for grabbing and tearing and some for crushing and grinding.
Mammals have three middle ear bones that greatly improves hearing.