How to Get Rid of Spiders in Your Basement Fast—and Stop Them From Coming Back

The cute itsy-bitsy spider rhyme goes out the window when you find a spider in your home, especially down in your basement, where they love to creep in to escape the cold.

According to entomologist Ngan Nguyen Rawlings, most spiders are venomous, but mainly to the other unwanted pests in your home. There are only a few species that can cause medical issues for humans.

Since a dark basement is a comfortable habit for many spiders, here’s a list of tips to get rid of them and even prevent them from coming in.

Why Spiders Love a Basement

Spiders are nocturnal and most basements are dark, cool, and damp — a spider’s dream environment. Even when the lights are on in the basement, if there is clutter it provides a good spot to spin a web or lay eggs.

There are cracks and crevices for hiding (and getting in from the outside). Basements also harbor plenty of food to prey upon like flies, mosquitoes, and ants.

How to Get Rid of Spiders in the Basement

Even if you don’t see spiders in your basement, if you see webs, you have spiders. Common house spiders like to hide, making them difficult to find. But even if you don’t see them, Rawlings suggests you should still take action to eliminate spiders and keep them from returning.

Remove Webs and Egg Sacs

Use a broom or vacuum to remove visible webs and spider egg sacs. Take the time to look under furniture and shelving. Be sure to dispose of the sweepings or empty the vacuum bag or cup outside into a sealed bag.

Get Rid of Clutter

Limit the number of hiding places for spiders and even get rid of a few hiding in cardboard boxes and papers by cleaning out clutter.

Vacuum Corners, Cracks, and Crevices

After removing clutter, vacuum every corner, crack, and crevice where a spider might hide.

Try Diatomaceous Earth

Diatomaceous earth (DE)is a silica made from the fossilized skeletons of tiny, aquatic organisms called diatoms. The silica has sharp edges that scratch the spider’s exoskeleton, absorb its natural oils, and cause it to dry out and die.

Diatomaceous earth is only effective when dry and should be applied in and near cracks where spiders hide or areas where they enter the basement like around door and window gaps.

Use a Commercial Insecticide Spray

Select a commercial insecticide spray that is specifically formulated for spider control. Following label directions, apply along the foundation and baseboards of the basement and in the cracks or gaps around windows, doors, plumbing, and electrical lines.

How to Prevent Spiders from Getting in Your Basement

• Seal cracks and openings. Using a flashlight, inspect the walls, floor, windows, and doors for cracks or gaps. Use caulk or weather stripping to seal these openings and add door sweeps to prevent spiders from getting inside. 
• Reduce clutter. Spiders love hiding in piles of boxes, clothes, or stored items. Keep your basement organized and clutter-free by using plastic bins instead of cardboard boxes. You’ll reduce the number of spiders, silverfish, firebrats, and roaches. 
• Lower the humidity levels. Spiders thrive in moist environments. Consider installing a dehumidifier to lower the humidity levels in your basement. Repair any leaky water lines, water heaters, or washing machine connections. Add a circulating fan to help keep the area dry. 
• Clean regularly. Even if you don’t use the basement often, it still needs to be cleaned and dusted regularly to remove webs and eggs. Pay extra attention to corners, window sills, and ceiling edges where spiders tend to build webs. 
• Install a storm door and windows. To tightly seal exterior access points, add a storm door and storm windows. Add a screen door and window screens that can be opened on dry, breezy days to help control moisture levels.
• Manage the landscaping. Trim bushes and shrubs so there is at least a three or four-foot gap from the foundation of your home. Limit the amount of mulch near the foundation and entrance areas where spiders can hide until they can get in your basement.
• Change outdoor lighting. Most insects are attracted to white lights that emit “cool” wavelengths of light like blues, purples, and ultraviolet. More insects means more food for spiders. Switch to yellow or sodium vapor bulbs to limit insect activity that draws spiders closer to your basement. Turn off outdoor lights whenever possible.

When to Call a Pest Pro

If you are dealing with a large infestation or see harmful spiders like a brown recluse or black widow, it’s best to call a professional exterminator.