Black widow spiders live in temperate climates on all continents except Antarctica. In the United States, they are primarily found in the South and in the West. Black widows are often found living in dark, dry environments, such as basements, hollow tree stumps and dense vegetation.
The female black widow is black with a red hourglass design on her back, while the male is a lighter color and has red or pink spots on his back. The female is about 1.5-inches long, about twice the length of the male. The black widow is the most venomous North American spider, but a bite from this spider does not usually cause death.