Catching a web across the face on the way to the laundry gets old fast. Spiders do earn their keep by eating other insects, but that does not make them welcome tenants behind the water heater.
Most basement spiders are harmless indoor species, and a few targeted changes make the space far less inviting. Below is how to get rid of spiders in the basement, which two species are worth a closer look, and how to keep the rest from coming back.
Key Takeaways
- Dry the basement out: The EPA recommends holding indoor relative humidity between 30 and 50 percent, and basement spiders and the insects they hunt both need damp air.
- Seal the entry points: Caulk foundation cracks and the gaps around pipes, windows, and doors so spiders cannot walk in.
- Spray peppermint oil: Peppermint repelled spiders in controlled choice tests; lemon oil, the tip most often shared online, had no measurable effect.
- Clear the clutter: Cardboard boxes, stored furniture, and debris are where basement spiders hide, spin webs, and lay eggs.
Why Do Spiders Like Basements?
Spiders like basements because one room hands them all three things they need at once: shelter, steady moisture, and prey.
Basements are dark, quiet, and humid, which copies the outdoor cracks and burrows spiders already favor. Nothing disturbs a web behind the furnace for months at a time.
Clutter makes it worse. Boxes, stored furniture, and piles of clothes give a spider endless undisturbed corners to build in, catch prey, and lay eggs.
Food seals the deal. If your basement already has flies, moths, or centipedes, spiders will follow, because they settle wherever the hunting is good. Cut the insects and you cut the reason spiders stay.
What Kind of Basement Spiders Are in My House?
The spiders in your basement are almost certainly common house spiders, cellar spiders, jumping spiders, or harvestmen, and none of those four is dangerous to people. North America has thousands of spider species, but only a small group is adapted to living indoors.
At the University of Washington’s Burke Museum, curator of arachnids Rod Crawford writes that “generally fewer than 5% of the spiders you see indoors have ever been outdoors.” The ones you keep running into are long-term residents rather than strays from the yard, which is also why scooping one up and releasing it outside rarely ends well for the spider.
Remember
Most basement spiders are harmless pest-eaters, but it is worth identifying them to rule out the two dangerous US species: the black widow and the brown recluse.
Common House Spiders
Messy, tangled cobwebs in ceiling corners and behind stored boxes point to the common house spider. They are brownish or grayish, they rarely leave the web, and they are more of a housekeeping problem than a health one. Clear the webs with a vacuum without any worry of a bite.
Jumping Spiders
These are the compact, fuzzy ones with oversized front eyes that turn to look at you. Jumping spiders build no webs at all; they stalk and pounce on insects, which is why you find them on windowsills in daylight rather than in a corner. They are harmless to people and they thin out the pests you actually mind.
Cellar Spiders
Often confused with daddy longlegs, cellar spiders have small bodies on very long, thin legs, and they favor dark, damp corners. When you disturb one it bounces in its web instead of running, which is a decent field mark.
An old urban legend claims their venom is deadly but their fangs are too short to break skin. Their venom is weak and they pose no threat to you or your pets. They are nuisance pests that leave wispy webs, and they eat other spiders, including ones you would rather not host.
Harvestmen
Harvestmen are the true daddy longlegs, and they are not spiders at all. They are arachnids without venom glands or silk glands, so they cannot bite you and they cannot make a web.
Body shape tells them apart from cellar spiders. Harvestmen have a single oval body segment; spiders have two, a head section and an abdomen. Harvestmen belong outdoors and usually wander in by mistake, so the fix is a door sweep, not a spray.
How to Spot the Dangerous Ones
Only two US spiders carry a medically serious bite, and both are easy to rule out once you know the markings.
A female black widow is shiny jet-black with a bright red or red-orange hourglass on the underside of her round abdomen, per the Illinois Department of Public Health (1). She spins a strong, messy web low to the ground in undisturbed spots, so check under storage shelves and behind the water heater with a flashlight rather than a bare hand.
A brown recluse is light brown with a violin-shaped mark behind its head, but that mark is not reliable on its own. The surer tells are its eyes and its legs: a recluse has six eyes arranged in three pairs where most spiders have eight, and its legs are one uniform color with no bands, stripes, or spines. Recluses also keep to a limited native range, roughly the central and southern states from Nebraska and Iowa down through Texas and across to Georgia. Outside that range, confirmed sightings are rare; in one national study of spiders mailed in by the public, only one of 581 specimens sent from California turned out to be a brown recluse. If you live well outside recluse country, what you found almost certainly is not one.
If you do confirm a widow or a recluse, skip the DIY spray and call a licensed exterminator, especially where children or pets use the space.
How Do You Get Rid of Spiders in the Basement?
Get rid of basement spiders in this order: vacuum up the spiders, webs, and egg sacs you can see, then treat or trap the perimeter, then seal the gaps and dry the room out so the survivors have no reason to stay. Skipping the last step is why spiders come back a month later.
The removal step itself splits two ways, chemical or physical. Here is what each one actually does.
Apply Residual Insecticides
For a heavy infestation, chemical barriers work well. Focus on perimeter sprays that create a treated band around your foundation, basement windows, and the sill plate.
Look for products containing bifenthrin or cypermethrin. These leave a residue that keeps working for weeks after application, so a spider picks up a dose walking in rather than needing a direct hit.
Safety First
Always read the label first. If you have curious toddlers or pets, choose a pet-safe formula or a natural alternative instead.
Use Diatomaceous Earth (DE)
Diatomaceous earth is a fine powder made from fossilized aquatic organisms. It feels soft to us but is microscopically sharp to anything with an exoskeleton.
Here is how to use it safely:
- Target entry points: Sprinkle a thin layer along baseboards, window sills, and door thresholds.
- How it works: When a spider crosses the powder, it scratches the waxy coating on the exoskeleton, so the spider dries out and dies.
- Keep it dry: DE only works dry, so a humid basement means reapplying more often. Use food-grade DE and a light dusting; a thick pile just gets walked around.
Try Ultrasonic Repellers
These plug-in devices emit high-frequency sound meant to drive pests away. They are a popular chemical-free option, but results are inconsistent and independent evidence is thin. Treat them as a backup to sealing and cleaning, not a standalone cure, and do not let one buy you an excuse to skip the caulk gun.
What Natural Remedies Repel Spiders?
Peppermint oil is the natural remedy with real evidence behind it, and white vinegar, sticky traps, and a vacuum handle the rest without turning your basement into a fume box.
Spray Peppermint Oil
Spiders smell and taste through sensory organs on their legs, so a strong, sharp scent is genuinely unpleasant to them. In a Simon Fraser University study published in the Journal of Economic Entomology, peppermint oil repelled brown widow and European garden spiders in more than 75 percent of choice tests, while lemon oil, the tip most often shared online, had no measurable effect (2).
Mix 15 to 20 drops of peppermint essential oil with water and a dash of dish soap in a spray bottle, then mist corners, windows, and doorways. The scent fades, so redo it every week or two. Eucalyptus and tea tree oils are reasonable alternatives; lemon is not, so save it for cleaning.
Use a Vinegar Solution
White vinegar contains acetic acid, which irritates spiders on contact and puts them off a treated surface.
Mix equal parts water and white vinegar in a spray bottle. Spray it directly on a spider to kill it, or along entry points as a deterrent. The smell is strong but fades within a few hours, and vinegar leaves no residue that a pet can pick up.
Set Sticky Traps
Glue traps are a non-toxic way to catch the spiders that wander rather than sit in a web. Place them flat against walls, behind furniture, and near doorways, since wandering spiders follow edges.
They double as a monitoring tool. A trap that fills up fast marks a high-traffic route that needs sealing, so check them before you decide where to caulk.
Vacuum Them Up
The simplest fix is often the best. Use a vacuum with a hose attachment to suck up spiders, egg sacs, and webs on the spot.
It beats squishing them, and it keeps stains off your walls. Empty the canister into an outdoor bin right away so nothing crawls back out.
Bonus Tip
Cats are natural hunters. You shouldn’t rely on a pet for pest control, but many cats are quick to spot and chase spiders that dart across the floor.
How Do You Keep Spiders Out for Good?
Keep spiders out by closing the gaps they walk through, holding the humidity down, changing the lighting that draws their prey, and clearing shelter away from the foundation. Killing the spiders you can see is only half the job.
Seal Cracks and Gaps
Spiders squeeze through tiny openings. Grab a caulking gun and work the basement inside and out.
Seal gaps around:
- Utility pipes: Check where wires and pipes pass through the foundation.
- Windows and doors: Replace worn weatherstripping and patch holes in window screens.
- Foundation cracks: Fill visible fissures in the concrete with silicone caulk.
Reduce Moisture
This is the step most people skip, and it is the one that does the most work. Spiders and the insects they eat both depend on damp air, so a wet basement is a standing invitation.
The EPA recommends holding indoor relative humidity between 30 and 50 percent, a range that also discourages the damp-loving insects spiders hunt (3). Run a dehumidifier to get there, fix leaking pipes, and make sure the dryer vent is sealed and running outside. Drying the basement out quietly starves the whole food chain.
Change Your Lighting
Insects swarm bright white light, and spiders follow the insects. Adjust the lighting and you cut off the food supply.
Swap standard bulbs near basement windows and exterior doors for yellow bug lights or sodium vapor lights. Those wavelengths are harder for insects to see, so fewer moths and flies gather by the house in the first place.
Maintain the Exterior
Your yard is the first line of defense. Bushes that touch the house act as a bridge, letting spiders walk straight onto the siding and hunt for a way in.
Trim vegetation at least 12 inches back from the foundation. Clear away wood piles, leaf litter, and debris near the house, since those are prime shelter for spiders and for the insects they eat.
Best Products for Basement Spiders
If DIY steps aren’t cutting it, these well-reviewed products help you get the situation under control faster.
Best Natural Spray: Mighty Mint Spider Repellent
Mighty Mint Spider Repellent is a plant-based spray built around high-concentration peppermint oil, which lines up with the deterrent research above.
Why we like it: It is safe around pets and children when used as directed, and it leaves the basement smelling clean instead of chemical. Use it around windows and baseboards as a preventive barrier.
Best Traps: TERRO T3206SR Spider & Insect Traps
TERRO Spider & Insect Traps are a standard glue board. They fold into a shelter that keeps the sticky surface clear of dust and away from pets.
Why we like it: The dark, enclosed design is exactly where spiders want to hide, and the glue also catches ants, crickets, and roaches. Tuck them into corners and behind boxes.
Best Ultrasonic Device: Neatmaster Ultrasonic Pest Repeller
The Neatmaster is a chemical-free plug-in with three modes for different infestation levels.
Why we like it: It covers a large area, which suits an open basement, and it runs hands-off. Just remember results vary, so pair it with sealing and cleaning rather than leaning on it alone.
How Do You Clean Spider Webs?
Clean spider webs with a vacuum and a long crevice wand, working from the ceiling down so falling silk lands on surfaces you have not done yet. Clearing old webs matters because a fresh spider will happily move into abandoned real estate rather than build from scratch.
Rough surfaces fight back. Silk grabs popcorn ceilings, unfinished joists, and bare brick, and a vacuum head skates over the top of it.
The Duct Tape Hack:
For a popcorn ceiling or rough brick, wrap duct tape around a paint roller with the sticky side out. Roll it over the webs and the adhesive lifts the silk without gouging the surface.
FAQs
A few common questions to help you stay ahead of your basement spider situation.
The Bottom Line
Getting rid of basement spiders comes down to taking away what they want: moisture, clutter, and easy prey. Vacuum the webs, seal the entry points, dry the space out, and keep peppermint or vinegar handy for the stragglers, and the basement stops being good habitat. If you spot a black widow or a brown recluse, or the numbers just won’t drop, call a licensed exterminator rather than pressing your luck.
