Spider Spider Spiders (order Araneae) are air-breathing arthropods that have eight legs and chelicerae with fangs able to inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every habitat with the exceptions of air and sea colonization. , at least 45,700 spider species, and 113 families have been recorded by taxonomists. However, there has been dissension within the scientific community as to how all these families should be classified, as evidenced by
Stinger receiving the venom. Spiders only bite, although some tarantulas have urticating hairs. Certain caterpillars also have urticating hairs. Organs that perform similar functions in non-arthropods are often referred to as "stings". These organs include the modified dermal denticle of the stingray, the venomous spurs on the hind legs of the male platypus, and the cnidocyte tentacles of the jellyfish. The term "sting" was historically often used for the fang of a snake, although this usage is uncommon today. Snakes are said, correctly, to bite, not sting. Stinger A stinger, or sting, is a sharp organ found in various animals (typically