The Western Black Widow (Latrodectus hesperus) is Utah’s most famous spider of medical concern. While they are a permanent fixture of the Utah landscape, understanding their habits and where they hide can significantly reduce your risk of a surprise encounter.
Black Widows are nocturnal and photophobic (they hate light). In the Utah climate, they seek out areas that remain cool in the summer and protected in the winter.
The hourglass:On the underside of the female’s bulbous, jet-black abdomen is a bright red (sometimes orange-yellow) hourglass shape.
The finishUnlike the "velvety" look of a ground spider, a widow is shiny and glossy, resembling black patent leather.
The webBlack widow silk is the strongest of all spider silks. Their webs are not pretty or geometric; they are messy, tangled, and irregular. They are usually built low to the ground.
The egg sacLook for a smooth, pea-sized, off-white sphere. If you see a "spiky" or "fuzzy" egg sac, it is likely a harmless brown spider—not a widow.
Black Widows are nocturnal and photophobic (they hate light). In the Utah climate, they seek out areas that remain cool in the summer and protected in the winter.
Window wellsPerhaps the #1 hotspot in Utah. The concrete walls and lack of disturbance make these perfect "incubators."
The garage "l-corner":Look where your garage door meets the floor and the wall. This corner is the primary entry point.
Outdoor furniture & BBQ coversThey love the dark nooks underneath patio chairs and inside unused grill covers.
Clutter & log pilesStacking firewood against your house is essentially an open invitation for a widow colony.
Are black widows actually deadly?While their venom is neurotoxic and a bite is a medical emergency, fatalities are extremely rare due to modern antivenom. Children, the elderly, and pets are at the highest risk.
"I found a brown spider with white spots, is it a Black Widow?”Possibly. Juvenile Black Widows start out tan or gray with white stripes or spots. They only turn jet-black as they mature.
Why do I find black widows in my basement?Widows follow the food. If your basement has crickets, beetles, or sowbugs, the widows will move in to hunt.
