Arachnids are air breathing, joint legged animals (Arthropods) with simple eyes, two main body parts (sometimes fused into one), four pairs of legs and no antennae. The class includes the spiders, harvestmen, scorpions, pseudoscorpions, mites and ticks. There are two additional pairs of limbs that are used for feeding, which could be mistaken for legs. The first, the chelicerae are often claw like and are used for eating or defence. The second pair are the pedipalps which may also be used for feeding, walking or reproduction.