Spiders in the Basement: Window Wells, Storage Rooms, and What Helps

If you live in South Jordan, there's a good chance your home has a basement, and a good chance you've met a spider or two down there this fall. Whether it's an unfinished storage room in an older neighborhood or a newer Daybreak basement with big egress windows, the lower level is where many Utah homeowners see the most spiders once the weather turns cold.

This post isn't about identifying every spider you find. (We've covered spider ID and black widows in earlier posts.) Instead, it's about where spiders settle in a basement over the winter, why those spots appeal to them, and the practical steps that make your basement a less comfortable place for them to stay.

Why spiders end up in basements

Spiders don't come downstairs for the warmth alone. A basement tends to offer the three things a spider wants most:

• Shelter. Quiet corners, boxes, shelving, and spaces behind the furnace or water heater rarely get disturbed.

• Food. Spiders eat other insects. If small bugs are getting into the basement through window wells, gaps, or drains, spiders will follow the food.

• Steady conditions. Basements stay more even in temperature than the rest of the house, and some stay a little damp.

In late summer and fall, many of the spiders people notice are wandering males looking for mates, which is why you might spot one running across the floor and not see a web nearby. By winter, the spiders you find are often ones that have settled in for the season, along with species like cellar spiders that can live indoors year-round.

Hot spot #1: Window wells

Window wells are one of the most common spider spots in Utah homes. They collect leaves, grass clippings, and moisture, and they sit right against the foundation and the basement window. That makes them a sheltered place for insects to gather and for spiders to build webs.

What helps:

• Clean them out. Remove leaves, weeds, and debris, ideally in fall and again in spring.

• Add a cover. Clear window well covers keep out leaves, snow, and small animals while still letting light in. Egress wells need covers that can be opened from inside for emergency escape, so choose one that meets code.

• Check the window seal. Look for gaps around the basement window frame and seal them with caulk so the well doesn't become a doorway inside.

Hot spot #2: Unfinished basements and utility rooms

Unfinished spaces have exposed joists, open wall cavities, and lots of edges where webs can hang undisturbed. The furnace and water heater area is a classic example.

What helps:

• Vacuum regularly. Run a vacuum with a hose attachment along the ceiling joists, corners, and behind appliances every few weeks. That removes webs, spiders, and egg sacs, and it lets you see whether new activity is showing up.

• Seal where pipes and wires come in. Gaps around plumbing, gas lines, and electrical runs can be filled with caulk or expanding foam (follow manufacturer guidance near gas lines and appliances).

• Check floor drains and sump areas. Make sure drain covers are in place and fix any standing water.

Hot spot #3: Storage rooms

The storage room is often the most spider-friendly room in the house. Stacks of boxes, holiday decorations, camping gear, and sports equipment create hundreds of hiding spots that might not get moved for months.

What helps:

• Switch from cardboard to lidded plastic totes. Cardboard has seams and folds that give spiders and other pests easy cover. Sealed plastic bins are much harder to get into.

• Lift storage off the floor. Wire or metal shelving with a little space underneath and behind it makes it easier to clean and spot activity.

• Pull things away from walls. Even a few inches of space between boxes and walls removes a lot of hiding places.

• Shake things out. Before you bring decorations or gear upstairs, give them a quick shake outdoors or in the garage.

Cut down on the food supply

Spiders stick around where there's something to eat. Reducing other insects in the basement is one of the best long-term ways to see fewer spiders.

• Reduce moisture. A dehumidifier in a damp basement can make the space less appealing to the small insects spiders feed on.

• Fix leaks under sinks, around the water heater, and near laundry hookups.

• Switch outdoor lights near basement windows and doors to yellow "bug" bulbs, or turn them off when not needed. Bright lights draw insects close to the house, and spiders follow.

• Keep the outside tidy. Pull mulch, rock, and leaf piles back from the foundation so fewer insects collect right next to the house.

Use sticky traps to see what's going on

Glue boards placed flat along walls, under shelves, and near the bottom of the stairs are a simple, low-cost way to monitor basement spiders. Many spiders travel along wall edges, so traps there catch wanderers and give you a sense of how much activity you actually have. Keep them out of reach of kids and pets, and replace them when they fill up or get dusty.

When to call a pro

Prevention handles a lot, but it's worth calling for help if:

• You keep finding spiders after cleaning and sealing what you can

• You're seeing lots of webs or egg sacs in storage areas

• You have kids or pets and want help putting a plan in place

• You're not sure what kind of spider you're dealing with

Standard Pest Control is based in Bluffdale, just south of South Jordan, and serves homes across Salt Lake, Utah, and Davis counties. A quarterly plan includes an exterior treatment around the foundation and entry points, and we're happy to point out window wells, gaps, and storage areas worth attention while we're there.

Frequently asked questions

Why do I see more spiders in my basement in the fall and winter?

In late summer and fall, many spiders, especially males, wander in search of mates, so they're more visible. Basements also offer shelter, steady conditions, and other insects to eat, so spiders that get inside tend to settle there for the winter.

Do window well covers really help with spiders?

They help. Covers keep out leaves and debris that hold moisture and attract insects, so fewer spiders have a reason to build there. Make sure any cover on an egress window can be opened from inside.

Will a dehumidifier get rid of basement spiders?

Not on its own, but it can help. Drier basements tend to attract fewer of the small insects spiders feed on. Combine it with vacuuming, sealing gaps, and better storage for the best results.

Are basement spiders dangerous?

Most spiders found in Utah basements are a nuisance rather than a danger. Black widows are the main exception to keep an eye on. See our earlier post on black widows for how to recognize them, and call a pro if you find one.

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