Black Widow Facts and Information

Basements, attics, garages, and cluttered storage areas are the most common spots, since they're dark, undisturbed, and offer good web-building corners. Outdoors, woodpiles, eaves, and dense vegetation near the foundation are frequent hiding spots as well.

Black widow bites can cause severe pain, muscle cramps, and other whole-body symptoms, making them a medical concern. Brown widow venom is similarly potent, but brown widows are less likely to bite and typically inject less venom, so their bites are usually less severe. If you're bitten by either spider, seek medical attention—especially if symptoms worsen, you're a child, an older adult, or you have underlying health conditions.

Black widows are shiny black with a red hourglass marking on the underside; brown widows are mottled tan to dark brown with an orange or yellow hourglass and have distinctively spiky egg sacs. Brown widows are generally less dangerous, since they inject less venom and are less aggressive, but both warrant caution.

Spiders move indoors looking for food, warmth, and undisturbed places to build webs — a spider infestation isn't a sign of poor housekeeping, it's usually a sign there's an available food source (other insects) or easy entry points. High humidity and a lack of natural predators can also play a role.