Ref: ITIS 82708 2002-09-18
The arachnids, Arachnida, are a class of invertebrate animals in the subphylum Chelicerata. They are chiefly terrestrial arthropods, some 65,000 to 73,000 species including the spiders, scorpions, harvestmen, ticks, and mites.
Arachnids are mostly carnivorous, feeding on the body juices of insects and other small animals. Many are venomous - they secrete poison from specialized glands to kill prey or enemies. Others are parasites, some of which are carriers of disease. Arachnids usually lay eggs, which hatch into immature adults.