Arthropods can be divided into four groups:
- Arachnids have eight legs. They do not have wings or antennae. Spiders are arachnids.
- Insects have six legs, two antennae and wings to fly. Flies are insects.
- Myriapods have long bodies with many pairs of legs. Centipedes are myriapods.
- Crustaceans are often aquatic and breathe with gills. Crabs are crustaceans.