Classifying animals: vertebrates and invertebrates: what children learn
Scientists classify living things into groups by looking at their characteristics: what they look like and how they live. Animals are first split into vertebrates (with a backbone) and invertebrates (without one). Vertebrates are divided into fish, amphibians, reptiles, birds and mammals. Invertebrates include insects, arachnids, molluscs, crustaceans and worms. In Year 6, children learn how and why living things are classified into broad groups, including micro-organisms, plants and animals.
This game asks which group an animal belongs to, or which animal belongs to a group. Some animals belong to two groups at once (a bee is an invertebrate and an insect), and the game never offers a second right answer. Watch for the classic surprises: a spider is an arachnid, not an insect; a woodlouse is a crustacean, related to crabs; an octopus is a mollusc, like a snail; and a whale is a vertebrate mammal, not a fish.
This topic covers the Year 6 statutory requirement in the National Curriculum in England (Living things and their habitats): pupils should be taught to “describe how living things are classified into broad groups according to common observable characteristics and based on similarities and differences, including micro-organisms, plants and animals”. Year 6 pupils are usually aged 10–11.
There is no direct equivalent in the US Common Core State Standards.
How to play
Answer 10 questions before the clock runs out. Tap an answer, or press 1 to 4. Each game has 10 multiple-choice questions and a 120-second timer. A wrong answer shows the correct one before moving on. You earn up to three stars depending on your score.
Step by step
- Backbone or not?. If the animal has a backbone it is a vertebrate. If not, it is an invertebrate.
- For vertebrates, look at the covering. Fur or hair: mammal. Feathers: bird. Dry scales: reptile. Smooth, damp skin: amphibian. Gills and fins: fish.
- For invertebrates, count the legs. Six legs: insect. Eight legs: arachnid. Lots of jointed legs and a hard shell: crustacean. No legs: worm or mollusc.
- Check the body. Molluscs have soft bodies and often a shell (snails) or tentacles (octopus).
- Use a classification key. Ask yes/no questions in order ("Does it have a backbone?", "Does it have six legs?") to reach the group.
Worked examples
Example 1: Which group does a spider belong to: insect, arachnid, mammal or fish?
Working: Count the legs: a spider has eight. Insects have six.
Answer: Arachnid.
Example 2: Which of these animals is a crustacean: woodlouse, bee, slug or newt?
Working: A bee is an insect, a slug is a mollusc and a newt is an amphibian. Woodlice have a hard shell and lots of legs.
Answer: The woodlouse.
Example 3: Is a whale a vertebrate or an invertebrate?
Working: A whale has a backbone and a skeleton made of bone.
Answer: A vertebrate.
Common mistakes and how to fix them
- Calling every small creature an insect. Count legs. Spiders (eight legs), woodlice (fourteen) and worms (none) are not insects.
- Thinking invertebrates are all small. Giant squid and octopuses are invertebrates. Size does not decide the group; a backbone does.
- Thinking an animal can only be in one group. Groups sit inside bigger groups: a bee is an insect, and all insects are invertebrates.
Activities to try at home
- Go on a minibeast hunt and sort what you find: insects, arachnids, molluscs, crustaceans and worms.
- Make a yes/no classification key for your family's pets or favourite animals.
- Look at pictures of an octopus and a snail together and talk about why both are molluscs.
- Print the worksheet and ask your child to give the clue for each answer.
Ideas for the classroom
- Give groups a set of animal cards and ask them to build their own branching classification key.
- Compare classification keys between groups: are there different correct keys?
- Extend to plants (flowering and non-flowering) and micro-organisms (bacteria, fungi such as yeast).
- Link to Carl Linnaeus and the idea of naming species, then play the game as a plenary.
Free printable game and worksheet
The free printable starts with a game sheet, such as a colour-by-answer picture, an answer maze or a secret-code joke, followed by a worksheet. Both use the same checked questions as the online game, and the answers are on the last page. Print it, or save it as a PDF from your browser’s print menu.
Open the free printable game and worksheet
Frequently asked questions
Is a spider an insect?
No. Spiders are arachnids. They have eight legs and two body parts; insects have six legs and three body parts.
Where do micro-organisms fit?
Micro-organisms, such as bacteria and some fungi like yeast, are living things too small to see without a microscope. They are not animals or plants. The game focuses on animals; the classroom ideas extend to the other groups.
Why are woodlice crustaceans?
Woodlice have a hard outer shell and many pairs of jointed legs, and they breathe with gill-like organs, like their relatives the crabs and lobsters. They live on land but need damp places.