Spiders that build funnel-shaped webs are usually known as funnel-web spiders, or agelenidae. There are more than 80 species of funnel-webs. These spiders are commonly found in North America and are mostly harmless to humans. There are, however, spiders in Australia that also produce funnel-shaped webs and can be very dangerous to humans. These spiders actually belong to another family, called hexathelidae, and are not related to North American funnel-webs. eHow.com