Getting rid of spiders comes down to three things: removing the ones already inside, cutting off their food supply, and sealing the gaps they use to get in. Spraying alone won’t solve the problem. Spiders aren’t insects, and most insecticides designed for bugs have limited effect on them. A combination of physical removal, habitat changes, and targeted barriers works far better than any single approach.
Seal Entry Points First
Spiders can squeeze through gaps as small as 1/16 of an inch, which means almost any crack in your home’s exterior is a potential doorway. The most common entry points are gaps around pipes, wires, outdoor faucets, gas meters, dryer vents, and cable lines where they pass through your foundation or siding. Windows and doors with worn weatherstripping are another major route.
Use silicone or acrylic latex caulk to seal cracks around windows, doors, and fascia boards. For larger holes around utility penetrations, expandable foam, steel wool, or copper mesh all work well. Install door sweeps at the base of every exterior door. A quick test: lie on the floor and look for daylight under the door. If you see light, spiders can get through. Garage doors need a rubber bottom seal, since vinyl seals tend to crack and shrink in cold weather.
Cut Off Their Food Supply
Spiders go where the eating is good. If your home has gnats, flies, moths, or other small insects, spiders will follow. The single most effective thing you can do is reduce the insect population inside and immediately around your house.
Outdoor lighting is a big draw for flying insects, which in turn attracts spiders. Switching exterior lights to yellow or sodium vapor bulbs dramatically reduces the number of bugs congregating near your walls and doorways. If you can, angle lights away from the building rather than mounting them directly on exterior walls. Inside, regular vacuuming picks up not just spiders and their webs but also the smaller insects they feed on. Pay special attention to corners, ceiling edges, and behind furniture where webs accumulate.
Keeping indoor humidity between 40% and 50% helps too, though not for the reason you might expect. Spiders themselves aren’t particularly drawn to moisture, but the insects they eat are. Most indoor pests prefer humidity above 60%. Running a dehumidifier in naturally damp areas like basements, crawl spaces, and storage rooms reduces insect populations, which makes those spaces far less appealing to spiders over time.
Physical Removal and Cleaning
Vacuuming is the fastest, most reliable way to remove spiders already in your home. It works on the spiders themselves, their webs, their egg sacs, and the insects they’re hunting. A cobweb duster or broom with an extension handle reaches ceiling corners and high shelves where webs tend to build up. Make this a weekly habit in problem areas, and spiders will have a much harder time establishing themselves.
Decluttering matters more than most people realize. Spiders love undisturbed spaces: cardboard boxes in the basement, piles of shoes in the closet, stacked items in the garage. Brown recluse spiders are particularly drawn to these environments and can live inside boxes, in unworn clothing, and in crevices of attics, crawl spaces, and closets. Switching from cardboard to sealed plastic bins and keeping storage areas tidy eliminates a lot of hiding spots.
Diatomaceous Earth for Long-Term Control
Food-grade diatomaceous earth (DE) is a fine powder made from fossilized algae that works mechanically rather than chemically. Its microscopic sharp edges damage a spider’s exoskeleton on contact, causing the spider to lose moisture and die from dehydration. It contains no toxic chemicals and remains effective as long as it stays dry.
The key to using DE is applying a very thin layer. A heavy dusting actually discourages spiders from walking through it, which defeats the purpose. Sprinkle it lightly along baseboards, in wall voids, around outlets, inside closets, and in basements or storage areas where you’ve seen spider activity. A powder duster helps get DE into tight or awkward spaces. Wear gloves and a dust mask during application, since the fine particles can irritate your lungs if inhaled. DE is not toxic to pets or children, but you still want to avoid breathing it in.
Do Essential Oils Actually Work?
Peppermint oil has some real science behind it. A 2018 study tested peppermint oil, lemon oil, and chestnuts against three spider species. Peppermint oil strongly repelled two of the three species. Chestnuts also worked well. Lemon oil, despite being widely marketed as a spider repellent, had no measurable effect on any of the species tested.
If you want to try peppermint oil, mix 10 to 15 drops per ounce of water in a spray bottle and apply it around windowsills, doorframes, and other entry points. It’s not a permanent solution and needs reapplication every few days, but it can be a useful supplement to physical exclusion methods. Don’t rely on it as your only strategy.
Why Insecticide Sprays Underperform
Standard bug sprays are formulated to kill insects, not arachnids, and the difference matters. Residual insecticides (the kind that leave a lasting chemical barrier on surfaces) work poorly against spiders. They’ll kill a spider that gets sprayed directly, but spiders walking across a treated surface days later often survive. Spider egg sacs are also relatively impervious to pesticides, so even a thorough spraying can leave the next generation untouched.
This is why pest control professionals often combine chemical treatments with physical methods like traps, dusting, and exclusion work. If you do use a spray, treat it as one tool among many rather than a standalone fix. Target it at cracks, corners, and other spots where spiders travel rather than broadly coating walls.
Identifying Dangerous Spiders
The vast majority of house spiders are harmless. In North America, the two species worth identifying are brown recluses and black widows.
Brown recluse spiders are tan to dark brown with a violin-shaped marking on their back, roughly 1/4 to 1/2 inch long. Younger ones or those that recently molted may lack the violin marking entirely. They live in the southeastern and midwestern United States and strongly prefer undisturbed indoor spaces: boxes, closets, attics, and crawl spaces. Their bite is painless at first. Within three to eight hours, the area turns red and begins to burn. In mild cases, discomfort resolves within a few days. In severe cases, the bite develops into an ulcer that can take several months to fully heal, sometimes accompanied by fever, chills, and vomiting.
If you’re finding brown recluses or black widows in your home, that’s a situation where professional pest control is worth the investment. Traps and targeted treatments are more effective than DIY sprays for venomous species.
When Professional Help Makes Sense
A one-time professional spider treatment typically costs $100 to $300, depending on home size and the method used. Spot spraying falls in that same range, while traps run $150 to $250 and fumigation (reserved for severe infestations) starts at $300 and can exceed $500. Quarterly service plans, which include follow-up visits and preventive treatments, average $350 to $750 per year.
Professional treatment makes the most sense in three scenarios: you’re dealing with venomous species, you have a large or persistent infestation that cleaning and sealing haven’t resolved, or you live in a region where spider pressure is constant. For most homes with an occasional spider sighting, the combination of sealing entry points, reducing clutter, vacuuming regularly, and managing outdoor lighting handles the problem without ongoing professional costs.