Spiders have Eight legs, no wings or antennae. Some spiders like moisture and are found in basements, crawl spaces and other damp parts of buildings. Others like dry, warm areas such as subfloor air vents, upper corners of rooms and attics. Hide in dark areas. They feed on insects, create webs and produce an egg sac that can spawn hundreds of new spiders. Only two species are harmful to humans in Canada. Sanitation is the best control measure.