1. MAMMALS

Those are the characteristics used to define the mammal class:

1. They might be herbivorous, carnivorous or omnivorous. We can distinguish it by the teeth they have. For instance, canines help carnivorous to tear flesh; molars help herbivorous to mill grain.
2. They give birth to “live young” with the exception of platypus and echidnas (monotremes).
3. Mammal mothers nurse their offspring with milk, even the oviparous ones.
4. They are warm-blooded and breathe through lungs.
5. Mammals are covered by hair or fur.
6. They usually live on land, but they can live in the water (whales, dolphins) or fly (bats).
7. Scientists have classified about 5,000 species as mammals.