House Centipede in Your Home? What It Means and How to Get Rid of It

A house centipede is a fast, long-legged predator that hunts insects and spiders inside damp basements, bathrooms, and crawl spaces. Seeing one usually tells you two things about your home. There is moisture it likes, and there are enough silverfish, spiders, or roaches to feed it. Fix both and the centipedes have little reason to stay.

House centipedes are near the top of the list of insects homeowners want gone, and near the bottom of the list of things in a basement that can do real harm. Their speed and their tangle of legs are unsettling, and they tend to appear at night on a bathroom wall or dart across the floor when a light comes on. What they really are is a symptom. The useful question is what they are eating and why your basement is damp enough to keep them alive.

How to Identify a House Centipede

The house centipede (Scutigera coleoptrata) has a flattened, yellowish gray body about 1 to 2 inches long, with three dark stripes running down its back. It has 15 pairs of long, banded legs, one pair per body segment, and the last pair is so long it can be mistaken for a second set of antennae at the rear. The real antennae at the front are long and threadlike as well, which makes the whole animal look far larger than its body. Young centipedes look like small adults with fewer legs, and they add legs each time they molt.

How Many Legs Does a House Centipede Have?

An adult house centipede has 30 legs, arranged as 15 pairs. That number surprises people who know them as thousand-leggers, a nickname many homeowners still use. House centipedes never come close to a hundred legs, let alone a thousand. If the many-legged creature you found is slow, round-bodied, and curls up when touched, it is a millipede instead, and our post on centipedes vs. millipedes explains how to tell the two apart.

House Centipede vs. Silverfish

These two get searched together constantly, partly because they share the same damp rooms and partly because one eats the other. Silverfish are wingless, carrot-shaped insects up to about half an inch long when fully grown, covered in silvery scales, with three bristly tails and a wiggling, fishlike way of moving. They have six short legs. House centipedes are larger, with 30 long legs that make them look spidery, and they move in fast bursts. If you see both in the same basement, the centipedes are almost certainly there because of the silverfish.

Why You Suddenly Have Centipedes in Your House

House centipedes need high humidity and a steady supply of prey to survive indoors. The species originally comes from the Mediterranean region, and in cold-winter states like Wisconsin, Iowa, Nebraska, and South Dakota it spends most of its life inside buildings, mostly in basements, cellars, and first-floor bathrooms where it stays cool, dark, and damp. House centipedes are nocturnal and very wary, so most of the centipedes living in a house are never seen at all. When one shows up in the open, it is usually out hunting, and regular sightings point to a population that has grown along with its food supply.

Where Do House Centipedes Come From?

Most house centipedes in a home were born there. They lay eggs in damp, hidden spots such as cracks in a basement floor, gaps behind loose baseboards, the undersides of stored boxes, and wall voids near plumbing, and the young take upwards of three years to reach maturity. Some also wander in from outside through foundation cracks, sump pits, floor drains, and gaps under basement doors. A home with an ongoing moisture problem can support the same centipede population for years.

Do House Centipedes Bite?

Very rarely, and technically it is not a bite. House centipedes have a pair of modified front legs called forcipules that inject venom into prey, and they can use them in self-defense if they are grabbed or pressed against skin. Stings to people are very rare, usually come from rough handling, and cause temporary, localized pain. House centipedes are not aggressive, and given the chance, they run.

What Do House Centipedes Eat?

House centipedes eat other arthropods, and they are not picky. Their prey includes silverfish, cockroach nymphs, bed bugs, flies, ants, spiders, and other small insects that share damp basements and bathrooms. They chase prey down rather than waiting in a web, using their speed and long legs to pin it before the forcipules deliver venom. Because their food supply is other pests, the number of centipedes you see rises and falls with the number of insects available to them.

Are House Centipedes Good to Have Around?

In a narrow sense, yes. They eat other pests and do not damage structures, food, or fabrics, which is why some people leave them alone. The catch is that a healthy centipede population is proof that other pests are living in your home in numbers large enough to feed it. We treat a house centipede sighting as a clue rather than a form of pest control.

Should You Kill a House Centipede?

Removing the one in front of you is fine, and a jar, a vacuum, or a quick trip outside on a piece of paper all work. Just know that killing individual centipedes changes very little. A house that keeps producing them has the moisture and prey to keep producing more, so the time is better spent on the steps below.

How to Get Rid of House Centipedes

Spraying the centipede you just saw does very little, since most of the population stays hidden and others will hunt in the same spots tomorrow. The approach that works removes the moisture and the prey that support them.

1. Lower the humidity. Run a dehumidifier in the basement, use bathroom exhaust fans during and after showers, and aim for indoor humidity at or below about 50 percent.
2. Fix water problems. Repair leaking pipes and dripping fixtures, caulk sump pump lids and seals, and redirect gutters and downspouts so water drains away from the foundation.
3. Cut off their food. Deal with the silverfish, spiders, and cockroaches that bring centipedes in, and our guide to silverfish in the home covers one of their favorite prey.
4. Seal hiding spots and entry points. Fill cracks in foundations and basement floors, caulk gaps along baseboards, and close openings around pipes and floor drains.
5. Clear clutter from damp areas. Move cardboard boxes, stacks of paper, and stored clothing off basement floors, where they hold moisture and shelter both centipedes and their prey.
6. Use sticky traps to monitor. Place them along basement walls, behind the water heater, and near floor drains to catch wandering centipedes and see where activity is concentrated.

How Long Do House Centipedes Live?

Longer than most household pests. House centipedes develop slowly, taking upwards of three years to reach maturity, and they can live up to seven years. That long lifespan is why an ignored moisture problem allows a population to quietly build in a basement over several seasons.

Why Are There Centipedes in My Bathroom?

Bathrooms produce the humidity house centipedes need every day, and the drains, tub surrounds, and gaps behind vanities give them dark places to hide close to prey. Centipedes found in bathtubs and sinks usually wandered in while hunting and could not climb back up the slick sides, rather than crawling up through the drain. Running the exhaust fan after showers and sealing gaps around the tub and plumbing makes a bathroom far less appealing.

When to Call a Professional for House Centipedes

If you keep seeing house centipedes after drying out the basement and sealing the obvious gaps, the bigger issue is usually the prey population feeding them, often silverfish, cockroaches, or spiders hiding where you cannot see. A professional inspection finds those sources along with the moisture problems behind them. Damp basements often bring spider crickets along with centipedes, so it is worth checking for both.

Fenix Pest Control helps homeowners across Wisconsin, Iowa, Nebraska, South Dakota, and Florida get centipedes and the pests they feed on under control, including through our Sioux Falls pest control service. Learn more on our centipede pest library page, or send us a message through the form below and a Fenix rep will be in touch within minutes.

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