feathers · gills · scales · amphibians · mammals · warm-blooded
There are many types of animals. Birds have feathers and wings. Feathers keep birds warm and help them fly. Most birds lay eggs with hard shells. Fish live in water. They breathe with gills and swim with fins. Their bodies are covered in scales. Amphibians can live on land and in water. Frogs are amphibians. They lay soft eggs in water. Baby frogs are called tadpoles. Mammals have fur or hair on their bodies. Mammal mothers feed milk to their babies. Dogs, elephants, and humans are all mammals. We are warm-blooded too.