What main group of animals do arachnids belong to?

Arthropods include several orders of invertebrates:

- insects

- arachnids (Spiders, scorpions)

- crustaceans (shellfish, snails)

The four living subphyla are:

Chelicerata - horseshoe crabs, scorpions, spiders, mites, ticks

Myriapoda - millipedes, centipedes

Hexapoda - insects (six legs)

Crustacea - crabs, lobsters, shrimp