House centipedes at home: what they are, whether they bite and how to make your home less inviting

How to identify a house centipede

House centipedes look alarming because of their legs, which grow longer toward the back: in females the last pair is more than twice the length of the body. Unlike most centipedes, they have large, well-developed eyes, and they run fast, holding the body high on their legs. If you swat one, legs often break off and keep twitching for several minutes, which is a defense against predators.

The young hatch with only 4 pairs of legs and gain more with each molt until they reach 15 pairs, so small ones with fewer legs are the same species.

Centipede vs millipede

Centipedes have one pair of legs on most body segments, with the legs attached at the sides, so they run fast; they are predators with venomous jaws. Millipedes have two pairs of legs per segment set under the body, move slowly, eat decaying plant matter and do not bite people or pets. When disturbed, a millipede curls up or releases a defensive chemical. Garden millipedes sometimes come indoors in large numbers after heavy spring rain, which usually points to a big population in the yard rather than inside the house.

Are house centipedes harmful?

House centipedes do not damage food, clothes, furniture or the building. Extension services describe them as harmless and even beneficial, because they eat household pests.

They can bite, but rarely do. They use modified front legs to inject venom into prey, and Washington State University notes they may give a painful bite if handled. Clemson's extension service compares a centipede bite to a wasp sting and says bites are generally harmless unless a person is very allergic to venoms; the jaws of smaller centipedes are often too weak to pierce human skin. Ohio State describes bites from larger centipedes as rare, usually causing short-lasting swelling or pain.

Why house centipedes appear: moisture and prey

Two things draw house centipedes and keep them breeding: damp and food. Unlike garden centipedes, the house centipede can complete its whole life cycle indoors and reproduces readily in heated buildings; in cold regions it cannot survive the winter outdoors. Females can produce up to 150 young, and adults can live for several years.

Penn State Extension lists the usual hiding and breeding places:

• Under concrete slabs, reached through expansion cracks or sump pump openings.
• Inside concrete block walls, through uncapped blocks or missing mortar.
• Floor drains without a water trap, especially those connected to a dry sump.
• Under cardboard boxes stored directly on a basement floor.
• Damp, cool crawl spaces.

Their prey is the second clue. If you see centipedes often, you may also have silverfish, firebrats, cockroaches, carpet beetle larvae, spiders, flies or moths in the house.

Dry out the house

Moisture control is the most effective long-term step, because it helps on both fronts: centipedes and their prey both need damp conditions.

1. 01

   Find the damp spots

   Check the basement, crawl space, bathrooms and the area under sinks. Look for condensation, musty smells, water stains and mold (mould in British English).

2. 02

   Dehumidify

   Run a dehumidifier in damp basements and similar rooms and empty or drain it regularly.

3. 03

   Ventilate

   Use the bathroom exhaust fan during and after showers, and make sure crawl spaces are ventilated; a sealed, conditioned crawl space is another option, see crawl space encapsulation.

4. 04

   Fix leaks

   Repair dripping pipes, leaking traps and failed seals around tubs and showers.

5. 05

   Move water away

   Grade soil so rainwater runs away from the foundation, and keep gutters and downspouts working; see gutter cleaning.

If the basement takes on water after rain, look at basement waterproofing or a sump pump.

Seal gaps and remove hiding places

• Seal cracks in foundation walls, slabs and expansion joints with a suitable filler, and fill gaps around lower windows, doors and pipes.
• Screen floor drains and caulk around the sump pump cover.
• Keep window and door screens in good repair.
• Clear a strip outside: Ohio State suggests removing wood, compost and leaf litter from a 3-foot strip around the foundation.
• Reduce clutter indoors: store boxes off the floor and away from walls, ideally in plastic bins.
• Vacuum: house centipedes can simply be vacuumed up or swept into a dustpan and released outside.

Sticky traps for monitoring

Sticky traps, sold as insect monitors or glue boards, are best used as a detective tool rather than a cure. Penn State Extension recommends placing them around the home to find out which prey insects are present, since frequent centipede sightings often point to a bigger problem with silverfish, cockroaches or other insects.

1. 01

   Place them where you see activity

   Along basement walls, behind the toilet, under sinks, in closets and near floor drains.

2. 02

   Number them

   Write a number and the date on each trap so you can compare catches.

3. 03

   Check every few days

   Note what you catch: centipedes, silverfish, cockroaches, spiders or beetles.

4. 04

   Act on the result

   Treat the prey problem you find, and focus drying and sealing where the catches are highest.

5. 05

   Repeat after changes

   Replace the traps after a few weeks to see if numbers have fallen.

Keep traps out of reach of children and pets, and place them flat against walls where they will not be stepped on.

Do you need insecticides?

Usually not. Washington State University recommends non-chemical methods first, and Clemson notes that pesticides give only temporary control unless the moisture and hiding places are also dealt with. Ohio State does not recommend indoor spot treatments and says total-release foggers (bug bombs) are ineffective. Where treatment is justified, extension guidance points to dusts such as boric acid or diatomaceous earth placed in cracks and voids, which have very low risk to mammals, or a band of a labeled product around the outside of the foundation. Always use a product labeled for centipedes and follow the label exactly.

When there are too many: calling a professional

Call a pest control professional when:

• You see centipedes in several rooms every night despite drying and sealing for several weeks.
• Sticky traps show another pest, such as cockroaches or a large silverfish population.
• You cannot find or reach the damp source, for example inside block walls or under a slab.
• There are signs of a hidden leak, water stains or mold; see leak detection.

Ask for an inspection that identifies the prey insects and the moisture sources, not just a spray. A good company will show you where centipedes are hiding and breeding and what to fix.

Sources

University extension guidance, checked on 27 October 2026.

• Penn State Extension · House centipedes ↗Size, legs by life stage, lifespan, number of young, harborage in slabs, block walls and drains, prey, sticky monitors, dehumidifiers, sealing and low-risk dusts.
• Ohio State University Extension · Centipedes and millipedes ↗Identification, legs that detach, indoor life cycle, bites from larger centipedes, centipede and millipede legs, 3-foot clear strip, sealing and ineffective foggers.
• Clemson Home & Garden Information Center · Centipedes ↗Body size, prey list, bite compared to a wasp sting, moisture as a warning sign and control.
• Clemson Home & Garden Information Center · Millipedes ↗Two pairs of legs per segment, diet, defense, no bites and indoor invasions after heavy rain.
• Washington State University Extension · House centipede ↗Night activity, damp hiding places, painful bite if handled, houseplant debris and non-chemical management first.
• NHS · Insect bites and stings ↗Washing and cooling a bite and the emergency signs of a severe allergic reaction.