Mammals are vertebrates or animals with backbones. They have large brains and a keen awareness of their surroundings. They are warm-blooded and have their skin covered with hair. Mammals give birth to their young ones, except for egg-laying platypus and spiny anteater, and suckle milk from the milk glands of females. You will be surprised to know that many animals, which are otherwise very different from one another, come under this category. For example, the cow, seal and bat have nothing in common, yet they come under the category of the mammals. Man is a mammal too. Many of the mammals are very peculiar. Some of these live on the land, some on trees while some others burrow holes inside the earth. There are some that live in water, also. Some of them are carnivorous while others are herbivorous. Some mammals are both carnivorous and herbivorous. Most of the time they live on the ground. The dugong, dolphin, whale, etc. are mammals that live in water. Amongst the flying mammals are the bat and colugo. Platypus is another peculiar mammal, which does not give birth to its young ones but lays eggs. It is found in Australia. Pangolin is a mammal that does not have teeth and lives on ants. The wolf, lion, cheetah, bear, cat, seal — all are mammals. There are about 4000 distinct species of mammals — the ones given above are just a few of them.