Size: Up to 1 ½ inches long, flat, thin, with 15 pairs of long and slender legs. The centipede’s antennae and legs give the pest the appearance of being up to 3 or 4 inches long. Adult females’ final pair of legs are up to twice as long as the centipede’s body.
Color: Brown, grey, or dark “dirty” yellow, semi-translucent looking. The centipede’s back bears three dark longitudinal stripes. Its legs are clearly banded light white or yellow and dark brown or black.
House centipedes are the only species of centipede with well-developed compound eyes. These eyes may be visible when the centipede lifts its head to run at high speeds. Despite possessing compound eyes and more detailed vision that most centipedes, the house centipede relies primarily on its long antennae to give it the considerable situational awareness it needs to hunt and chase prey at high speeds.
Like other arthropods, house centipedes have clearly segmented bodies. Each of the centipede’s distinct body segments bears a single pair of legs. House centipedes have as many body segments as they do pairs of legs, so as they grow new legs, they also grow new body segments. Fully-grown house centipedes, therefore, possess 15 pairs of legs.
As is the case with many other centipedes, house centipedes’ smallest two front legs are actually modified, hollow fang-like piercing implements, which they use to envenom and paralyze their prey while hunting. Centipedes rarely “sting” humans with these leg-implements, and the few attempts they do make rarely break the skin. At worst, a house centipede sting is comparable to a bee sting in terms of pain.
House centipedes are characterized by their ability to run very quickly. At top-speed, these centipedes can cover 16 inches per second! The pest is also notorious for jerky, sudden movements. In 1902, US Dept. of Agriculture entomologist C.L. Marlatt wrote: “(the house centipede) may often be seen darting across floors with very great speed, occasionally stopping suddenly and remaining absolutely motionless, presently to resume its rapid movements, often darting directly at inmates of the house, particularly women, evidently with a desire to conceal itself beneath their dresses, and thus creating much consternation.”
House centipedes are opportunistic predators, hunting and feeding on a wide of variety of insects including spiders, smaller arthropods like silverfish, sowbugs, millipedes, roaches, fly larvae, beetles, and more.
House centipede diet depends almost entirely on what kind of prey they can encounter. The pest has been observed hunting and killing snails and worms, as well as other very small non-insect animals. In some circumstances, house centipedes may kill and eat each other.
House centipedes relay on the paralyzing venom they inject their prey with while hunting, so they cannot successfully hunt or kill anything too big to be affected by their venom. The pest also uses its fangs or legs to clamp down on prey while they attempt to inject it, so they struggle to hunt anything too fast, big, or strong to hold down.
The house centipede’s speed, its ability to leap almost twice the length of its body, its powerful legs, and its venom-injectors make it a highly effective predator of other pests. In fact, in natural habitats the house centipede is considered a highly beneficial insect for the part it plays in thinning pest populations.
House centipedes are capable of using both their fang mandibles and their many legs at once while restraining prey, and so they’re capable of dispatching multiple small insects at once. House centipedes often use their legs to pin, hold down, or beat prey while they administer their venom, a technique called “lassoing”. When hunting larger prey, such as wasps, the centipede may inject venom and then retreat and wait for the venom to immobilize its victim.
House centipedes tend to be quite temperature sensitive. They prefer to inhabit protected, dark enclosures in humid places. During the day, house centipedes avoid sunlight and remain largely inactive under dark cover. Their flat bodies enable them to fit into very snug openings, such as beneath concrete slabs, pipes, boxes, or furniture. They also commonly hide in cracks in walls or floors.
Centipedes can be considered nocturnal predators, because they generally wait until late at night to forage for prey. If they live in an environment that is always dark, like a basement, attic, or crawl space, however, they may hunt during any time of day.
Unlike most centipedes, house centipedes can and will reproduce indoors. The pest seems to prefer to lay eggs in particularly humid environments. Reproduction occurs in early-to-mid spring.
During reproductive season, male centipedes locate mates using their antennae. When a mate is found, they spin a silk pad containing their sperm. Female centipedes use this silk pad to fertilize the eggs they lay. In laboratory observations, female centipedes laid between 63 and 151 eggs in their lifetime (over the course of several reproductive seasons).
Fertilized eggs take around two weeks to hatch. The mother remains with the eggs during this period, and protects larvae after they hatch. House centipede larva resemble their mature counterparts, except they are smaller and have 4 pairs of legs instead of 15.
House centipedes mature through 5 larval stages and 4 adolescent stages before full maturity. During each stage they molt and grow new legs and body segments. The 5 larval stages have 5, 7, 9, 11, and 13 pairs of legs, respectively. Each adolescent stage has the full 15 legs.
House centipedes are quite long-lived and take much longer to mature than many insects. It takes house centipedes up to two years to reach reproductive maturity. In the proper environment, the pest may live between 3 and 7 years.
Signs of Infestation
House centipedes don’t leave behind many signs of infestation. They don’t tend to infest buildings in high numbers, and they don’t damage plants or structures. The easiest way to tell you have house centipedes to see one hunting or encounter one beneath an object it was using as shelter.
House centipedes hide in dark and humid locations during the day and come out at night. Look for them beneath storage containers like cardboard boxes, display cases, or furniture in basements, warehouses, storage areas, pantries, attics, or crawl spaces. When deprived of their cover, house centipedes will run toward the nearest dark cover.
House centipedes frequently infest areas where they can access moisture, because they will die in dry places. They’re commonly encountered in bathrooms and boiler rooms, especially at night. Finding a house centipede may also be a sign that there’s a nearby plumbing leak.
House centipedes can detach their legs if they get caught by a predator, injured, or caught under something. Finding these legs can be difficult, but if you happen upon one, chances are you have a centipede in your building. Centipedes also molt frequently as they mature, leaving behind flakey shed skin.
Treatment and Prevention
House centipedes feed on other pests, so keeping them from infesting your building means treating for other pests. Look for places where spiders, beetles, roaches, or other small centipede prey could get into your building and cut off their access points. Seal and weatherproof door and window frames. Use caulk to fill in cracks and gaps in the walls, floor, and foundation, especially around utility pipes. Repair any damaged property.
Cleaning your property frequently and thoroughly helps prevent pest infestation and also deprives house centipedes of the shelter they need. Don’t let food, garbage, or other clutter build up on the floors or on countertops. Sweep, vacuum, and/or mop to prevent dust and dirt accumulation. Deal with pest infestations quickly and decisively to keep centipedes from capitalizing on them.
House centipedes require a lot of moisture and humidity to survive. In fact, usually living in buildings for extended periods should dry out and kills centipedes. If you have centipedes for a long time, it’s probably a sign that your building is too humid. Look for plumbing leaks, patch up drafts, install proper ventilation and drainage, and consider investing in a dehumidifier.