Mammals have hair
The polar bear is a mammal and has an outer covering of hair. Its hair keeps it warm in its cold environment and allows it to appear white, camouflaging with the surrounding ice to avoid being spotted by its prey from a distance.
Mammals breathe through lungs
All mammals, even the ones that live in water such as whales and dolphins, breathe through lungs! They swim up to the surface of the water to take air into their lungs and exhale through their blowholes!
Mammals give birth to live young
Bats are the only mammals capable of true flight! They give birth to live young in the safety of caves, away from predators.
Mammals suckle their young
Mammals are the only animals that suckle their young – mothers feed their babies with milk until they are able to find their own food.