Warm blooded animals are the animals which have a constant body temperature regardless of any change in the temperature outside. They are called the homeotherms and they can generate heat in their body due to their metabolism during cold temperatures outside. Birds and mammals are the warm blooded animals.
The mammals differ from the other warm blooded animals in the following characteristics.
1. The mammalian middle ear contains the three bones called the malleus, stapes and incus but the ear of the birds have only one bone transferring the sound.
2. The mammals have the mammary glands. The females nourish their young ones by the secretion of milk from the mammary glands.
3. They have the body hair or fur on their body surface protecting them.
4. Most of the mammals are viviparous and give birth to their young ones rather than laying eggs as in case of birds.
