Spiders have an ominous, but often undeserved reputation. Though most spiders are venomous and considered predators, of the thousands of species found in the US, few are actually considered a health threat. In fact, spiders are actually helpful in controlling other pests in the home or garden since they feed on other insects and spiders. They generally bite and inject venom into their prey. Spiders, however, rarely bite humans.
Although spiders are often unpopular, the venom of most species is not very toxic to humans, usually resulting in no more than a slight swelling, inflammation, or itching sensation. Most spiders’ fangs are too small or weak to puncture human skin. Spiders usually will not attempt to bite unless accidentally trapped against the skin or grasped, although some species actively guard their egg sacs or young.
Two spiders that can be a health risk are the brown recluse and black widow.
One of the most common misconceptions about spiders is that they are insects. Spiders are arachnids and are actually closely related to mites, ticks and scorpions. Spiders have two body parts (cephalothorax and abdomen), eight legs and usually six to eight eyes, while insects are classified by having three body parts (head, thorax and abdomen), six legs, and generally two compound eyes or up to three single eyes. The average life span of a spider is usually one to two years, but some can live five years and up to 20 years.