Female is one-half inch long; shiny black, with hourglass-shaped red mark on underside of abdomen. Can be found almost anywhere, indoors or out; prefer to build their nests close to the ground. They eat insects trapped in webs made by females. Contrary to popular belief, female is usually unsuccessful in any attempt to eat the male after mating; 300 to 400 eggs are laid in silken cocoon, hatch in about 10 days. Black widows are not aggressive, and will not bite unless provoked. However, they are poisonous. If bitten, seek medical attention; bites are rarely fatal.