- All mammals are viviparous, except for monotremes, which are oviparous.
- Mammals can be carnivores, herbivores or omnivores.
- Baby mammals drink their mother's milk until they can find their own food.
- All mammals breathe with their lungs.
- Most mammals have fur or hair.
- Most mammals have four legs and move on land, but mammals have flippers to move in water.
Elephants, bats, and dolphins are mammals.
Echidnas are monotremes. Monotremes are oviparous mammals. They live in parts of Australia and New Guinea:
