Mammals are air breathing animals. Mammals can be identified because of the hair on their bodies. Another characteristic that all mother mammals have are mammary glands. The function of the mammary glands is to produce milk and for their babies. Only mammals have diaphragm. A diaphragm is a thin layer of muscle, located around the ribs. Diaphragm's main use is to help with breathing. These are just some of the characteristics used to identify a mammal from other animals. Humans are considered to be mammals as well.