There are more kinds of insects, more individual insects and a larger
total mass of insects than all other animals combined.
Arthropods are invertebratesthey dont have skeletons inside their bodies. Instead, every arthropod has an exoskeletona tough covering on the outside which provides support for muscles and organs.
Arthropods have jointed legsin fact, thats what gives them their name. Arthropod comes from the Greek for "jointed foot."
Arachnids, such as spiders and scorpions
Crustaceans, such as crabs and lobsters
Myriapods, such as centipedes and millipedes