With a body about the size of a dime, mature female Black Widow Spiders are shiny, jet black and usually have a red to orange hourglass-shaped mark on the underside of the abdomen. They are most likely to bite when provoked or accidentally disturbed. Males are about half the size, do not have the hourglass marking and are less likely to cause a dangerous bite

Damage From Black Widows

The poison of a female Black Widow Spider is 15 times stronger than that of a rattlesnake, but a Black Widow Spider bite is rarely fatal. The area around the bite will become swollen and painful, and the venom can cause headaches, nausea, weakness, back spasms and other painful symptoms. Children, the elderly and sick people are at greatest risk from dying from a Black Widow Spider bite. Anti-venoms are widely available and very effective.

Black Widow Spiders prefer dark, undisturbed areas. They often hide out in basements, attics, garages, wood piles and in cluttered closets. Their webs appear chaotic rather than intricately structured, and the silk is very strong and sticky. Egg masses are smooth, round, yellowish white balls.

Where Black Widows are Found Geographically

Black Widow Spiders are common throughout the United States.

Related or Similar Pests 

Brown Widow Spider. Brown Recluse Spider.



Cultural Controls

  • Reduce clutter and clean-up on a regular basis to discourage spiders from becoming established.
  • Elevate stored boxes on shelves or pallets so that it is easy to check beneath for spiders and other insects with a flashlight and mirror.
  • Seal entry points around the exterior of your home.
  • For additional methods of controlling Black Widow Spiders, contact your local cooperative extension service.