* Crustaceans usually have 10 legs. Their exoskeletons contain a mineral substance that makes them very hard. Most crustaceans live in the sea. Lobsters, crabs and prawns are crustaceans.

* Arachnids have 8 legs and long bodies. Most are terrestrial and carnivorous. Spiders and scorpions are all arachnids.

* Myriapods have many legs and long bodies. They need a damp environment to survive, and mostly live on or under the ground. Myriapods eat insects and othe small animals. Centipedes and millipedes are examples of myriapods.

* Insects are the most numerous group of arthropods. Many insects also have wings. Most are found on land, but some live in fresh water.

Bees, butterfly, grasshoppers, mosquitoes and beetles are all insects.

3.- ARTHROPODS

Arthropods can be classified into 4 groups: