What is an invertebrate?

In a nutshell

Invertebrates are animals without a backbone. They can be further divided into three groups that share similar characteristics: insects, arachnids and molluscs.

	key characteristics	examples
Insects	Six legs and three body parts.	Butterflies, beetles, ants and houseflies.
Arachnids	Eight legs and two body parts.	Scorpions and spiders.
Molluscs	Slimy foot and sometimes have a shell.	Snails, slugs and squids.

Classification key

Classification keys can help identify animals. The below classification key can be used to identify the three groups of invertebrates.

Science; Living things and their habitats; KS2 Year 4; What is an invertebrate?