Black Widow Web Identification Checklist

Are you worried about black widows in and around your home? Learn to identify a black widow spider web and you’ll always know what type of spider you’re dealing with, and when it’s time to contact a pest management professional.

What are the keys to black widow web identification?

The thing that strikes most people about black widow webs is how chaotic they appear. There isn’t a discernible pattern at first glance. Rather, it appears haphazard, tangled and crisscrossed. It’s also typically constructed close to the ground. Because of this location and the strength of the black widow’s silk, leaves and other debris will often get tangled in the widow’s web. Their silk is so strong, if you waved your hand through it, you’d hear it rip. In fact, in World War II, black widow silk was used to make crosshairs for gun sights.

What does a black widow spider web look like?

The uneven web of a black widow might look disorderly, but it’s actually carefully planned out and constructed. There are three structural levels to the web. At the top, strong supporting threads secure the web so that flying prey and debris can’t easily rip the web free. The central area consists of a tangle of threads, and the bottom portion of the black widow web is where the vertical ‟traps” for crawling prey are weaved. The widow will typically either sit upside down in the middle of the tangled center, or retreat to the ground and wait for prey to get caught in the web. Sometimes, these spiders will rest above the web, dropping down from as far as 10 feet onto their unlucky meals. The webs are constructed during the day and always near sources of food, such as caterpillars, mosquitoes, grasshoppers and other similar prey.

Where do black widows make their webs?

Black widows are shy spiders and prefer to build their webs in secluded areas. Outdoors, you’ll find black widow spider habitats around crevices in stone walls, rodent burrows, woodpiles, under bushes and rocks, and even in the lower branches of trees. Near the house, black widow spider webs can be found in and around garages, sheds, attics, crawl spaces, cracks in the foundation and underneath window eaves. Inside the house, they might take up residence inside boxes, seldom-worn shoes and around the corners of rooms that don’t get a lot of foot traffic.

Is there any surefire sign it’s a black widow spider web?

The most foolproof way to tell a widow’s web from another spider’s is to know what a black widow looks like. These spiders are clumsy when they’re not directly touching their webs, so they use them as a defense from predators, not only to capture prey. As such, they spend most of their time in their web. Female black widows measure approximately 1.5 inches in length, fully extended. Males only grow to be about 1 inch in length, and are not considered a threat to humans. Both sexes have black, hairless, glossy bodies. The poisonous female has the telltale red hourglass marking on the underside of her abdomen. Since she sits ‟belly up” in the web, the hourglass marking is visible. Males have three light streaks on their abdomens. If you see a spider sitting in the web matching this description, you’ve successfully identified a black widow web. Also, if attacked, they drop from their web and ‟play dead.”

Black widow bites can be dangerous. If you see a black widow or a black widow spider web, call Terminix® right away and let the professionals help eliminate the threat.