Chances are you've seen a house centipede; those many-legged grayish-yellow bugs with floppy antennae that scurry across the floor and cause humans to engage in unexpected screaming and jumping on chairs. House centipedes (Scutigera coleoptrata) are distinguished from other centipedes by their longer legs. The longer legs affect the way the common insect moves, creating a sort of "rolling" motion that makes it looks like they have many more legs than they do.
The house centipede moves very quickly and always seem to dart out in front of you when you're vulnerable, like when you're just out of the shower or carrying something fragile. For people who tend to be startled or frightened by insects, these leggy prehistoric-looking creatures are the stuff of nightmares.
Still, house centipedes are basically harmless to humans, and they're effective predators of other insect nuisances, including roaches, flies, silverfish, and termites. So, if you can learn to not be terrified of them, you should let them do their thing.
Then again, if you find them to be a nuisance or source of annoyance (some of the most common phobias involve insects and spiders, after all), then you'll want to do what you can to at least lessen the possibility that you'll find one in your home.
What Are House Centipedes?
The house centipede is an arthropod, a genus that includes insects as well as centipedes, millipedes, arachnids (spiders) and crustaceans (such as lobsters). The house centipede originated in the Mediterranean but now can be found across Europe, Asia, and North America.
It has 15 pairs of legs, the last pair nearly twice the length of the body on adult females. The centipede goes through six larval molts and four adult molts before reaching maturity. Females can survive several years and produce up to 150 offspring. They tend to hide during daylight and come out at night to forage for prey.
5 Ways to Remove House Centipedes
Maybe you're not convinced that their habit of eating silverfish and flies makes house centipedes desirable houseguests. If you want to get rid of them, it may be tempting to crush them with a tissue, but they can leave very sticky stains behind. Try these natural/non-toxic methods instead or hire a professional exterminator:
If you see house centipedes emerging from various cracks or crawl spaces, try using a high-powered vacuum cleaner to suck them out. Empty the vacuum cup or vacuum bag into a sealable plastic bag and dispose of it in an outdoor trash can.
This powdered substance made from crushed insect exoskeletons is a very effective remedy for all kinds of indoor pests. The microscopic jagged edges of the powder pierce the body of the house centipedes and also dry out the fat and oils contained inside, slowly killing them. Sprinkle liberally around cracks, door thresholds, and in corners, especially in damp areas. You can leave it for a few days, then vacuum up. Wait at least 24 hours before vacuuming. Repeat as needed.
Get rid of their food supply
This means eliminating roaches, silverfish, flies, moths and the other tasty insects that house centipedes love to snack on. Sticky traps, vinegar, cedarwood spray, salt and/or baking soda sprinkled on thresholds and in corners, and the aforementioned diatomaceous earth are all safe methods for eliminating these pests.
Clean and/or seal external entry points
House centipedes are attracted to things that help them hide. Clearing any debris that may become damp (such as leaves, dirt, grass clippings, or weeds) from around the perimeter of your home may help deter them from entering.
Clean drains with vinegar or bleach
It's not uncommon to find house centipedes near bathroom or kitchen drains or in the cabinets under the sink. Pouring some vinegar or bleach down the drain will usually keep them out. Use one-half cup of vinegar, wait an hour, then another half cup. For bleach, use a 50:50 water/bleach solution.
Never mix vinegar and bleach. The combination can form a toxic chlorine gas.
What Attracts House Centipedes?
These carnivorous bugs eat other bugs, but mostly they just hide in dark crevices until they decide to scurry out and startle you. They like damp dark places, and tend to be more active at night, though if you disturb one of their hiding or resting places, you may see them scuttling about during the day. You may find them under your sink or in the bathtub occasionally, as those spots combine the damp and dark conditions they love so much. They tend to be fairly dormant in the winter (they prefer temperate climates) and begin to be more active in spring. Once temperatures begin to get colder in autumn they may want to find an indoor hiding place. They also seek out damp spaces in the midst of drought.
Unlike the moths that eat wool and grain, termites that infest wood, and silverfish that destroy clothing fibers, glue, and paper, there is no real damage caused by house centipedes. They don't carry disease like mosquitos, either. So there are worse bugs to have in your home, even if they do tend to startle people when they zoom across the floor.
How to Prevent House Centipedes
Using preventive measures will eventually make your home a less hospitable place for house centipedes, and they may just leave on their own, seeking greener pastures (and damper basements). There are a few methods you can use to deter house centipedes from taking up residence in your home.
Lower humidity levels
Similar to silverfish, preventing the presence of house centipedes begins with lowering the level of humidity in your home. Though many people use humidifiers in winter for health reasons, this should not conflict too much with prevention measures, as house centipedes are not generally as active in the winter. Using a dehumidifier in warmer months may make a difference in the number of house centipedes in your home. It is especially important to repair plumbing leaks and keep basement and attic spaces dry.
Seal cracks and openings
Making sure cracks are sealed near windows can help keep house centipedes out.
Clean up damp areas
Check out damp areas around the foundation of the home. Remove leaves and weeds and seal cracks to prevent any seepage of moisture into your home.
Do House Centipedes Bite?
House centipedes rarely bite humans, but they do have a venom that can be painful if a bite pierces the skin, so care should be taken when handling them.
Diatomaceous Earth. National Pesticide Information Center.
Vinegar. National Capital Poison Control Center.
Undheim, Eivind A B et al. Centipede venom: recent discoveries and current state of knowledge. Toxins, vol. 7, no. 3, pp. 679-704, 2015. doi:10.3390/toxins7030679