Spiders in your Basement? Here’s How to Get Rid of Them

Last updated: October 2026

The short answer: To get rid of spiders in your basement, vacuum up the spiders, webs and egg sacs you can see, clear out clutter and cardboard, and place sticky traps along the walls. To keep them from coming back, seal the gaps they use to get in, bring the humidity down, and cut back on the insects they come to hunt. If spiders keep returning after a thorough cleanup, a targeted professional treatment will usually finish the job.

Your basement can hold plenty of unwelcome surprises, from water in your basement to a large spider staring back at you from the corner. The good news is that most basement spiders are harmless, and a few practical changes make your basement far less inviting to them.

Why Are There So Many Spiders in My Basement?

Spiders settle where they can find food, shelter and quiet. Most basements check all three boxes:

• Food: Spiders follow the insects they eat. If moths, flies, crickets or silverfish are getting into your basement, spiders will follow them.
• Moisture: Damp basements attract the small insects spiders feed on, which in turn brings in more spiders.
• Clutter: Stacked boxes, stored furniture and corners that rarely get disturbed give spiders hiding spots and places to build webs.
• Shelter: Like other pests, spiders move indoors to get away from heavy rain, heat and cold.

If you have noticed a sudden jump in spiders, timing may be the reason. In the Carolinas, our technicians see the most spider activity in late summer and early fall, when spiders that hatched earlier in the year are grown and searching for mates.

How to Get Rid of Spiders in Your Basement

Work through these steps in order. Each one makes the next more effective.

1. Vacuum spiders, webs and egg sacs. Start at the ceiling and work down to the floor, paying attention to corners, window wells and the spaces behind stored items. Egg sacs are small, silk-wrapped balls, and each one can hold many young spiders, so removing them matters as much as removing the spiders themselves. When you are done, seal the vacuum bag and take it straight to your outdoor trash.
2. Clear the clutter. Get rid of anything you no longer need, and move the rest off the floor and away from the walls. Swap cardboard boxes for plastic bins with tight-fitting lids, since cardboard gives spiders and other insects easy places to hide.
3. Set sticky traps. Place glue traps flat against the walls and in corners, where spiders travel. They catch wandering spiders and show you where activity is heaviest.
4. Treat cracks and crevices, and skip the bug bombs. If spiders keep showing up after a cleanup, a targeted treatment in cracks, gaps and corners works far better than a fogger. Total-release foggers rarely reach the hidden spots where spiders live. Always follow the product label.

How to Keep Spiders Out of Your Basement

Getting rid of the spiders you see is only half the job. These steps help keep new ones from moving in:

• Seal entry points. Caulk cracks in foundation walls, fill gaps around pipes and utility lines, and add door sweeps and tight-fitting screens to basement doors and windows.
• Lower the humidity. A dehumidifier helps make your basement less attractive to the insects spiders eat. The EPA recommends keeping indoor humidity between 30 and 50 percent. If your basement stays damp even with a dehumidifier running, it may be time to look at basement waterproofing.
• Cut off the food supply. Exterior lights draw night-flying insects, and spiders set up webs nearby to catch them. Switching to yellow bulbs near basement doors and windows attracts fewer insects.
• Clean up outside. Move firewood, leaf piles and debris away from the foundation, and trim back shrubs and vines that touch the house.
• Keep up the routine. Sweep down new webs as soon as you see them, and recheck your sticky traps every few weeks.

Do Natural Spider Repellents Like Peppermint Oil Work?

Scents like peppermint oil are a popular way to repel spiders, but the evidence is limited. In a 2018 lab study published in the Journal of Economic Entomology, peppermint oil and chestnut appeared to repel two of the three spider species tested, while lemon oil had no effect on any of them. The researchers noted that these scents may discourage spiders from entering an area, but they are unlikely to drive out spiders that have already settled in.

If you want to try peppermint oil, use it as an extra step alongside sealing, decluttering and moisture control rather than a replacement for them.

Are the Spiders in My Basement Dangerous?

Most spiders you find in a basement are harmless, and many actually help by eating other pests. A few species in South Carolina are worth knowing, though:

• Black widows: Shiny and black with a red hourglass marking underneath. The southern black widow is found throughout South Carolina and favors dark, undisturbed places.
• Brown widows: Gray to brown with an orange or yellow hourglass. They are now established in parts of the state.
• Brown recluses: Less common in our area than many people think, and often confused with harmless look-alikes such as wolf spiders.

Widow spiders are shy and rarely bite unless pressed against skin, which is why it helps to wear gloves when moving stored items. If you are not sure what you are looking at, send us a picture or read more about dangerous spiders and how to avoid them. If you think you have been bitten, contact a medical provider.

When to Call a Professional

It is time to bring in help if:

• Spiders keep returning after you have cleaned, decluttered and sealed
• You are finding egg sacs or fresh webs every week
• You think you have black widows or brown recluses
• You are seeing other signs of a spider infestation, such as large numbers of the insects spiders feed on

Our spider pest control service starts with an inspection to identify the species and find what is drawing them in, whether that is moisture, entry points or another pest. From there, we treat the areas where spiders are active and help you address the conditions behind them so you are not dealing with the same problem next season.

Call us at 864.578.8822 or schedule an appointment online.

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Frequently Asked Questions

When are spiders most active?

In the Carolinas, spider sightings usually peak in late summer and early fall, when many species are fully grown and looking for mates. You may also notice more activity in spring as warmer weather brings insects, and the spiders that hunt them, back out.

Does a dehumidifier help get rid of spiders?

A dehumidifier helps indirectly. It makes a damp basement less appealing to the insects spiders feed on, so fewer spiders have a reason to stay. It works best combined with sealing entry points and clearing clutter.

Should I kill the spiders in my basement?

You do not have to kill every spider you see, since most are harmless and eat other pests. Vacuuming up spiders, webs and egg sacs is the simplest way to clear an area. If you are seeing a lot of spiders or suspect a black widow or brown recluse, it is worth having a professional take a look.