Animals: groups, body parts and what they need

Animals are sorted by what they have

Scientists put animals into groups by features you can see and count: how many legs, whether the body is covered in fur, feathers or scales, and whether it has a backbone. Birds have feathers and two legs; fish have scales and fins; insects have six legs and three body parts.

Body parts do jobs

Every part has a purpose: wings for flying, fins for swimming, claws for gripping, a beak for the kind of food that animal eats. When a question asks “why does this animal have…”, the answer is always a job, not a description.

What every animal needs

All animals need food, water, air and a place to live. Plants make their own food; animals cannot, so they must find it. That one difference explains most of what animals spend their day doing.