For the most part, spiders are harmless and generally beneficial by keeping the insect populations in check. Spiders are seldom aggressive and bite only when threatened or injured. Few spiders bite people and the venom of most is harmless. Most infestations require both methods. And remember, the better you understand any pest, the easier it will be to eliminate or control.
Spiders are the largest group of arachnids.
There are more than 35,000 named species worldwide, including about 3,000 in North America, but probably most spider species are still awaiting identification. These predators live almost everywhere - on the ground, under rocks, inside and underneath playground equipment, among grasses, on plants, in tree branches, in underground caves and even on the water. Spiders frequently stray into dwellings or other indoor habitats, or may be accidentally introduced on firewood, laundry that has been hung out to dry, and on flowers. Spiders will also sneak into our homes in boxes, clothing or furniture. In windows and near outdoor lighting, web-building spiders often construct webs because insect prey may be attracted at night by the lights and by air currents.