Cats Especially Sensitive to Black Widow Spider Venom

Fortunately, black widows are not aggressive. They bite only when provoked or when their webs are disturbed.

About an inch long, the black widow spider is shiny black or brown with a red or orange hourglass-shaped mark on the underside of its abdomen. phonecat/Shutterstock

Q: Our indoor-outdoor cats are fascinated by the spiders and spiderwebs around our house. I am concerned that some of the black, shiny spiders may be black widows. Are black widow spiders dangerous to cats?

A: Cats are especially sensitive to the toxin of the black widow spider, the most venomous spider in North America.