Getting rid of black widows requires a combination of direct removal, targeted spraying, and making your property less inviting to them. These spiders are shy and nocturnal, so you’ll rarely see them during the day. That works in your favor: once you know where they hide, you can systematically eliminate them and keep them from coming back.
Know Where Black Widows Hide
Black widows typically nest outside, close to the ground, in dark, sheltered spots. Their favorite habitats include holes between bricks, gaps around pipes, cracks in foundations, rock walls, and cluttered areas around garages, sheds, and outbuildings. In garages, they build webs near doors, around vents, and anywhere insects pass through. They retreat into these hiding spots during the day and come out at night to sit in their webs, usually within three feet of the ground.
Outdoors, check under the lips of plant pots, beneath picnic tables, inside trash can handles, around lawn chairs, and inside children’s plastic playhouses or toys with hollow spaces facing downward. Indoors, look in undisturbed corners of basements, crawl spaces, and storage areas.
Their webs are distinctive. Unlike the neat, circular webs of garden spiders, black widow webs are irregular, tangled cobwebs with no recognizable pattern. They include vertical support threads above and below a central area where the spider waits. The silk of a mature female is remarkably strong. If you run your finger through one, it makes an audible ripping sound. That strength is a reliable clue you’re dealing with a black widow rather than a harmless cobweb spider.
Remove Spiders, Webs, and Egg Sacs Directly
The most immediate step is physical removal. A vacuum cleaner is your best tool. Use it to suck up any spiders, webs, and egg sacs you find. When you’re done, seal the vacuum bag while the motor is still running (this prevents spiders from escaping and keeps dust contained), then dispose of the bag in an outdoor trash can.
Egg sacs are small, roughly the size of a marble (about 3/8 inch across), white to tan, and spherical. They hang suspended in the web. Each one contains an average of 255 eggs, so destroying them is critical. If you leave egg sacs intact, you’ll be dealing with hundreds of spiderlings in a matter of weeks. Look for egg sacs in late fall and winter especially, though they can appear at other times of year.
Always wear leather or thick work gloves and closed-toe shoes when working in areas where black widows may be hiding. Move items slowly and deliberately rather than plunging your hands into dark spaces.
Apply Insecticides Strategically
For chemical control, synthetic pyrethroid sprays are the most widely available and effective option for homeowners. Products sold at hardware stores under brand names like Spectracide Triazicide, Ortho Home Defense, and Bayer Advanced Multi-Insect Killer contain long-lasting pyrethroids that kill spiders on contact and leave a residual barrier.
Apply these sprays at the base of all exterior doors, around garage and crawl space entrances, around foundation vents, and near any utility openings where pipes or wires enter your home. Treat a band two to six feet wide along the ground around your foundation’s perimeter, and spray two to three feet up the foundation wall. A compressed air sprayer or hose-end sprayer gives you better coverage than a standard trigger bottle.
Microencapsulated formulations (where the active ingredient is sealed in tiny polymer capsules) offer longer-lasting protection. These products release their active ingredient gradually, providing residual control for up to three months on exterior surfaces and up to 12 months indoors. This slow-release approach means you don’t need to reapply as often.
One important limitation: because black widows hide in deep cracks, behind objects, and inside voids, spray coverage is often poor in the exact spots they inhabit. Spraying alone won’t solve a serious infestation. It works best as a barrier to prevent new spiders from moving in, combined with the direct removal methods above.
Seal Entry Points Into Your Home
Exclusion is the most permanent solution. Black widows follow their prey (insects), so any gap that lets bugs in will eventually let spiders in too. Lie on the floor near your exterior doors and check for light coming through underneath. Even a gap of 1/16 inch is enough for insects and spiders to enter.
Start with these high-priority areas:
- Door sweeps: Install them at the base of every exterior door. Caulk along the bottom outside edge and sides of door thresholds.
- Utility openings: Seal gaps where pipes, wires, outdoor faucets, gas meters, dryer vents, and cable lines enter your foundation or siding. Use silicone caulk, cement, expandable foam, or copper mesh depending on the size of the hole.
- Windows and screens: Caulk cracks around window frames, door frames, and fascia boards. Repair any tears in window and door screens.
- Foundation cracks: Fill visible cracks in your foundation with appropriate sealant.
This is labor-intensive work, but it pays off for years. Every gap you seal removes a potential entry point not just for black widows but for the insects they eat.
Reduce What Attracts Them
Black widows go where the food is. Outdoor lighting near doorways and garages draws moths, beetles, and other insects, which in turn attract spiders. Switching to yellow or sodium vapor bulbs (which attract fewer insects) or moving lights away from the house and toward the yard can make a noticeable difference.
Clutter is the other major factor. Piles of firewood, stacked lumber, cardboard boxes on garage floors, old equipment, and general debris all create the dark, undisturbed crevices black widows prefer. Move firewood at least 20 feet from the house and elevate it off the ground. Store items in sealed plastic bins rather than cardboard boxes. Clear vegetation and ground cover away from your foundation. The less clutter touching your home’s exterior, the fewer hiding spots are available.
Regularly sweep or knock down cobwebs around your home’s exterior, especially near doorways, eaves, and garage entrances. This persistent disturbance makes the area less attractive to spiders looking for a stable web site.
When to Call a Professional
If you’re finding black widows repeatedly despite your efforts, or if they’ve established themselves in areas you can’t easily access (inside wall voids, crawl spaces, or dense landscaping around your property), professional pest control is worth the investment. Exterminators use commercial-grade products and application equipment that reaches deep into cracks and voids where consumer sprays can’t. Most companies offer free quotes, and treatments typically use products that are safe around children and pets once dry.
A professional is also the better choice if you have young children, elderly family members, or anyone with a compromised immune system living in the home, since black widow bites pose a greater risk to these groups.
What to Do if You’re Bitten
Black widow venom attacks nerve endings in your muscles. A bite can cause severe, bodywide muscle pain and cramping that goes well beyond what you’d expect from a small puncture wound. If you suspect a black widow bite, wash the area with soap and water, apply an ice pack wrapped in a thin cloth (never directly on skin), and elevate the bite if possible. Then get medical attention right away. If you managed to capture or kill the spider, bring it with you, but providers can usually diagnose based on symptoms alone.