A whale is a mammal.
It breathes air. It is not a fish. A dolphin is a mammal too. An orca is the biggest dolphin.
How animals are grouped
People sort animals so we can talk about them. One big split is the backbone.
Has a backbone
- Mammals have hair or fur. Mothers make milk.
- Birds have feathers.
- Reptiles have dry scales.
- Amphibians often start in water.
- Fish live in water and use gills.
No backbone
- Insects have six legs and three body parts.
- Other animals here have no backbone, and they are not insects.
Easy to mix up
A penguin is a bird.
It cannot fly. It still has feathers, so it is a bird.
A shark is a fish.
Its skeleton is cartilage, not bone like yours. Cartilage is the bendy stuff in your ears and nose.
A spider is not an insect.
Insects have six legs. Spiders have eight.
A bat is a mammal.
It is the only mammal that truly flies. A bird is not a mammal.