The house centipede adult has 15 pair of legs with the last pair (on adult females) nearly twice the length of the body, which is one to one and one-half inches in length. This gives the centipede an overall appearance of being from three to four inches in length (including legs and antennae). The legs are banded light and dark, and the body is a dirty yellow with three longitudinal, dark stripes. Newly hatched larvae (rarely seen) have four pair of legs. During the next five larval molts, the centipedes will have 5, 7, 9, 11 and 13 pairs of legs. On the next molt the centipede is considered an adolescent and will have 15 legs during each of the next four molts – when it becomes an adult.
House centipedes feed on silverfish, firebrats, carpet beetle larvae, cockroaches, spiders and other small arthropods. If house centipedes are seen frequently, this indicates that some prey arthropod is in abundance, and may signify a greater problem then the presence of the centipedes.
Locations within structures that have been known to provide safe harborage for house centipedes include beneath concrete slabs. The centipedes enter the house through expansion cracks, around sump pump openings or other breaks in slab integrity. Inside cement block walls. The centipedes can enter through uncapped blocks, missing mortar between blocks and around pipes where they pass through the walls. In floor drains without water traps, especially those drains that are connected to dry sumps. Under and in cardboard boxes that are stored on slabs. In any damp, cool location, such as unexcavated areas (crawl spaces) under the house.
Prevention Tips
Seal all cracks and crevices and reduce harborage.
Install screens in basement floor drains to prevent centipedes from entering from dry sumps.
Correct any moisture problem.
Reduce the humidity by utilizing dehumidifiers.
Repair leaky pipes.
Grade the soil around the building to facilitate water movement away from the foundation.
Treat for other insects as this is a food source.