Is the false widow dangerous?

The false widow is capable of a bite that stings briefly, but not dangerous. Bites are uncommon and produce local pain and swelling comparable to a bee sting, resolving without treatment. Not medically significant.

How do you identify a false widow?

No hourglass. This is the whole test. Dark purple-brown rather than true glossy black.

Where do false widows live?

The false widow is found across most of the United States, in habitats including indoors, basement and garage.

False Widow

Stings only

Steatoda grossa · also called cupboard spider, dark comb-footed spider

The false widow is the spider that causes most black widow scares indoors. It is the right shape, the right shine and builds the right kind of web — but it has no hourglass, and it is not medically significant. It also preys on actual widows.

Bite risk: Bites are uncommon and produce local pain and swelling comparable to a bee sting, resolving without treatment. Not medically significant.
Size: Body 6–11 mm. Body about a pea, similar in shape to a widow but slightly smaller.
Appearance: Dark purplish-brown to near black with a slightly glossy, bulbous abdomen, often with faint pale crescent markings near the front. No hourglass of any kind.
Web: Tangle web in dark, undisturbed indoor corners — cupboards, garages, under sinks.
Found in: indoors, basement, garage
Family: Theridiidae
Range: Most of the United States

How to identify a false widow

No hourglass. This is the whole test.
Dark purple-brown rather than true glossy black.
Faint pale crescent or band across the front of the abdomen in many individuals.
Smooth round egg sacs, not spiky.

How it behaves

Web-bound and reclusive. Drops and plays dead when disturbed.

What the false widow is confused with

One observation settles each of these.

Black widow →

Look at the underside for a red hourglass. If there is none, it is not a widow.

If you think you were bitten

Most suspected spider bites are not spider bites. Studies of patients presenting with a “spider bite” repeatedly find that the large majority are bacterial skin infections — frequently MRSA — which need antibiotics rather than reassurance. A spreading, painful, pus-filled sore is far more likely to be an infection than a spider.
Wash it, ice it, and watch it. Clean the area with soap and water, apply a cold pack, and keep an eye on it.
Get medical care if the wound spreads or darkens, if you develop cramping, sweating, fever or severe abdominal pain, or if you are confident it was a widow or a recluse.
Bring the spider only if it is already dead and to hand. Do not go looking for it. Doctors treat symptoms, not species.

In the US, the Poison Help line is 1-800-222-1222. This site is a reference, not medical advice.

Not sure it was a false widow? Identify it step by step →