Cannibalistic Brown Widow Spider Will Eat Black Widow Species

A bite from this arachnid won't give you as many problems as black widow bites, but it's still no fun. Vinicius R. Souza / Shutterstock

The brown widow spider (Latrodectus geometricus) is a lesser-known relative of the infamous black widow. The first brown widow spider was discovered in Los Angeles in early 2000. A member of the cobweb spiders, it is now found in warm, urban areas worldwide.

Although their bites are rare and less severe than those of black widow spiders, these arachnids are still worth watching out for — and learning about, especially if you live in southern California or other regions where these widow species are common.

How to Identify Brown Widow Spiders

Brown widows are slightly smaller than black widow spiders, with females measuring about half an inch (1.3 centimeters) in body length.

Their coloration ranges from light to dark brown, with mottled patterns on their abdomens and legs. One of their most distinctive features is the vivid orange or bright red hourglass marking on the underside of their abdomen, which sets them apart from other spider species.

Brown widows are often mistaken for the more famous western black widow or southern black widow. However, their lighter coloring and the unique spiky texture of their egg sacs help distinguish them.

Female brown widows, like female black widows, are larger and more noticeable than males, which are smaller and less colorful.

Are Brown Widow Spiders Dangerous?

While brown widow venom is venomous, it's less potent than the venom of black widow spiders. Black widow bites will send you to the hospital, and while brown widow bites aren't nearly as severe, they can still cause mild pain, redness and swelling.

These spiders are shy and nonaggressive, biting only when provoked or accidentally pressed against the skin. These venomous spiders pose little threat to humans — though, brown widows often attack black widow species.

Where Are Brown Widows Commonly Found?

Brown widows can be found in urban areas worldwide, including southern California, parts of South America, the Middle East and even Africa. They thrive in warm climates and often build their webs in human-made structures like outdoor furniture, garden tools and building crevices.

Unlike black widows, which prefer more secluded habitats, brown widows are more likely to build their cobwebs in open, accessible areas. They are most active at night, hiding during the day to avoid predators.

What Attracts and Deters Brown Widow Spiders?

Brown widow spiders are attracted to areas with abundant prey, such as insects that get caught in their sticky cobwebs. Urban areas provide plenty of hiding spots and food sources, making them ideal for these adaptable arachnids.

To deter brown widows, regularly inspect outdoor furniture, storage areas and other potential nesting sites for webs and egg sacs. Cleaning up clutter and sealing cracks in walls can help keep these spiders out of your living spaces.

If you find webs with spiky egg sacs, remove them carefully using a broom or vacuum to prevent the next generation of spiders from hatching.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.