Mammals are animals which raise their young on milk and typically give birth to live young. Most mammals are covered with hair or fur, the difference between the two is fur grows to a certain length and then falls out, while hair continues to grow indefinitely, which is why some will take their dog to the groomer regularly for hair cuts and the cat never needs one. Most mammals have specialized teeth that help them to cut or chew their food. Compared to other vertebrates, mammals have highly developed nervous systems and sensory organs, and have intelligence and resourcefulness that few other animals can match. Mammals are probably the most familiar members of the animal kingdom, including our cats and dogs, elephants, whales and dolphins, and the species that now dominates life on earth, human beings.
Mammals inhabit just about every corner of the Earth.
You will also find mammals high on treacherous mountain slopes where the air is thin, right down to the deepest depths of the oceans where the pressure would instantly crush an animal from a land habitat. Marsupial is the common name for the group of mammals we recognize by the pouch in which the female will carry offspring. Some more well known marsupials include the kangaroo, koala, wombat, and opossum. Also including the lesser known numbat, bandicoot, ringtail possum, and thylacine. The most important trait the marsupials possess is the lack of a true placenta in pregnant females.