Five major ways that Mammals differ from other animals are as foloows:
1. Mammals are the only animals that nurse their babies on the mother's milk.
2. Among all animals, only mammals have hair.
3. Generally, mammals bear their young alive, unlike other animals that mostly lay eggs.
4. Mammals possess sweat glands, which helps to maintain a regular body temperature
5. Only mammalian vertebrates have tooth sockets. (The only exception to this is the Crocodile, which is a reptile that has tooth sockets)