It can’t be an insect; it has too many legs, 15 pair to be exact. House centipedes are not insects, but they are arthropods and belong to a special class of arthropods known as centipedes. These strange-looking creatures are occasionally seen darting across the floors of homes throughout the country, frequently startling the occupants. Unlike other centipedes, house centipedes are able to breed indoors, especially in areas that are moist or humid. They are also able to run much faster than most other ground-dwelling arthropods, reaching speeds approaching one MPH. Considering their size—mature specimens are slightly over an inch long not counting their legs and antennae—this really is fast, but it is hard to appreciate just how fast one MPH can seem until you have seen one on the run. Like other centipedes, the front pair of legs is modified into a pair of hollow fang-like structures, which they use to capture prey (see photo). Bites to humans are uncommon unless centipedes are handled or accidentally pressed against the skin. House centipedes are long-lived, taking over two years to reach maturity. Because of this long life cycle, and the fact that they are predators, house centipedes are rarely very numerous. Most infestations can be counted in single digits, rather than hundreds.
Control: Because house centipedes are predators of other household insect pests, some people consider them to be beneficial. Of course, there are also many people who just can’t stand the things and don’t want them running about the house. Efforts to control house centipedes should focus on controlling the other household insect pests on which they feed, and on physical exclusion practices that make it more difficult for insects and other arthropod pests to enter the building. Practices that reduce indoor moisture and humidity also aid in control.
See Extension Publication 2443, Control Household Insect Pests, pages 33-35, for information on how to control silverfish and “occasional” household insect pests, and see pages 4-10 for information on cockroach control. Controlling these pests will deprive house centipedes of food and most of the insecticide spray treatments used to control these pests also provide direct control of house centipedes. See Bug-Wise Newsletter No. 7 of 2014, for more information on physical exclusion methods.
Blake Layton, Extension Entomology Specialist, Mississippi State University Extension Service.
The information given here is for educational purposes only. Always read and follow current label directions. Specific commercial products are mentioned as examples only and reference to specific products or trade names is made with the understanding that no discrimination is intended to other products that may also be suitable and appropriately labeled.