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Invertebrates

Animals can be classified as either vertebrates or invertebrates.

Invertebrates are animals that don't have a backbone. Some have soft bodies, like worms, slugs and jellyfish. Other invertebrates, like insects, spiders and crustaceans, have a hard outer casing called an exoskeleton. This protects their body a bit like a suit of armour.

Vertebrates have a backbone inside their body. They include mammals, birds, fish, amphibians and reptiles.