Arachnida - Spiders, Scorpions, Mites, Ticks

There are over 60,000 known species in this class. Like most arthropods, arachnids have eight jointed legs and an exoskeleton. Arachnids have two sections to their bodies - the prosoma and the opisthosoma. The promosa is the front part of the body. The promosa includes the arachnid's head and thorax or cephalothorax.

Arachnids have four pairs of walking legs, a pair of jointed jaws with fangs called the chelicerae, and a pair of antenna-like pedipalps. The opisthosoma is the rear half of the body and it has no appendages. Arachnids have no antennae.

Many species of spider spin webs to trap prey. Scorpions are the largest members of the arachnid order. They have 6-12 appendages and a stinger at the end of their tail that they use to kill or paralyze their prey. Mites and ticks are parasites. They need a host to survive. They feed off of the blood and body fluids of their host.