The Black Widow will seek shelter anywhere – inside or out – though most often their nests are close to the ground. These venomous spiders are not normally aggressive, only biting when provoked. And, while their bite is rarely fatal, medical attention should be sought immediately if bitten.
Female black widows are roughly 1/2 inch long with an hour glass shaped red mark on their abdomen. While the legend is that they will eat the male after mating, the female is usually unsuccessful in this. 300 to 400 eggs are produced and wrapped in a silk cocoon, and will hatch in about 10 days.
Black Widows feed on insects trapped in the web made by the female.
Black widow spiders are considered the most venomous spiders in North America. (Factoid Source: National Geographic)