Please confirm that you are not located inside the Russian Federation
The link you have selected will take you to a third-party website. We do not control or have responsibility for the content of any third-party site.
Enter search terms to find related medical topics, multimedia and more.
A black widow spider is typically one-half to one inch long. The female, which is more common, has a reddish hourglass marking (shown) on the abdomen.
Photo courtesy of Mike Cardwell (Extreme Wildlife Photography, Sacramento, CA).