All young mammals feed on their mothers' milk until they can find and eat food by themselves. All mammals have four limbs. All mammals breath air. All mammals are warm-blooded. All mammals produce milk for their young.
All mammals have hair even elephants and whales.
Mammals have been around for 200 million years. There are about 4,000 different species of mammals alive today. The two most diverse groups of mammals are rodents and bats. Mammal Diversity Mammals are divided up into groups of related animals, called Orders. Below you'll find the name of the most common orders and some examples.