Mammals belong to the group of vertebrate animals. They are characterized by having their bodies covered with fur, being born in the womb of the mother (viviparous) and by nursing their young with milk from mammary glands.
Mammals are warm-blooded animals, i.e. they are able to regulate their body temperature so that it remains constant, whether it is cold or warm, and they breathe through their lungs.
Depending on the type of food, mammals are classified by: herbivores, i.e. those that feed on plants, such as horses, sheep or elephants; -carnivores that eat animal meat - such as lions, wolves and bears; and omnivores that feed on both plants and animal flesh, such as humans and some primates.
In the world there are 5500 species of different mammals.