Centipedes (Latin, = hundred foot) are exclusively predatory arthropods belonging to the class Chilopoda (Latin, = fang foot). Centipedes are unusual among the arthropods (insects, spiders, etc.) because their exoskeletons lack the waxy coating that helps to retain water inside the body. Centipedes require moist environments to survive. Outdoors, centipedes thrive in soil, leaf litter, under rocks and inside dead wood or logs. The house centipede, Scutigera coleoptrata (order Scutigeromorpha), can live its entire life indoors, and it is often found in basements and bathrooms. Most home-invading centipedes are encountered in buildings and homes after spring warm-up and in the fall when cooler temperatures encourage them to seek shelter. They have a frightening appearance but are generally considered harmless. Large species (larger than two inches long) can bite with their front "fang legs" but this is very infrequent and generally resulting in short-lasting swelling or pain. Centipedes are essential predators in our ecosystem, feeding on numerous other arthropods.
|Stone Centipede||Soil Centipede|
Stone centipedes are very common in Ohio, have only 15 pairs of legs as adults, and they belong to the order Lithobiomorpha. They are aggressive predators, commonly found living under rocks. These arthropods have lost their compound eyes, or sometimes, have no eyes at all. Soil centipedes (order Geophilomorpha) are very slender, have 29 pairs of legs or more, are completely blind, and are most commonly encountered when digging in the soil.
The large centipedes (order Scolopendromorpha) are relatively rare in Ohio, but can be found in southern Ohio forests. In Ohio, we have a couple of species that can get over three inches in length (tropical species can be over a foot in length) and can bite if handled. Large centipedes have 21–23 pairs of legs.
Centipedes are typically reddish-brown, flattened, elongated animals with many segments, most of which have a single pair of legs. Although the name suggests that centipedes have a hundred legs, these arthropods typically have 15 to over 30 pairs of legs. Often, each pair of legs is longer than the pair before it, reducing the chance that they will overlap and collide. The legs of centipedes are attached to the side of the trunk segments, which allows for them to run much faster than millipedes that have their legs attached under the body. The first pair of legs have been rotated forward so that they rest around the mouth. Each leg is modified by ending in a hollow claw that is attached to a poison gland. These are used to grab prey and quickly subdue them with toxins.
The house centipede is unusual by having very long legs. They are yellowish-gray with three dark, long stripes down the back. The legs are marked with alternating light and dark bands. The actual body length can range from about an inch to two inches, but the 15 pairs of very long legs makes them appear much larger. The last pair of legs can be more than twice its body length and are used as a kind of rear-facing antennae. A pair of very long slender antennae extends forward from the head. House centipedes, unlike other centipedes, have well-developed faceted eyes. They move very rapidly and when struck, the legs are easily detached. Detached legs will wiggle for several minutes which can be very disturbing to the average person.
Life Cycle and Habits
Centipedes are generalist predators, preying on insects, spiders and other small arthropods. They are considered to be beneficial but are often considered nuisance pests when they invade homes and buildings. Their long legs allow them to run swiftly to capture prey or escape when disturbed. Centipedes are mostly nocturnal and may inhabit many types of habitats including forests, deserts and caves. Centipedes are long-lived, most capable of surviving from three to seven years. They overwinter as adults and lay eggs in the spring. Centipedes do not copulate for reproduction. The female centipede collects the spermatophore deposited by the male, often after he performs a courtship dance. Females deposit up to 60 eggs in moist, hidden areas. Females often curl about their egg mass to protect them from other arthropods. Eggs may take up to three months to hatch. Young centipedes look like the adults, but often have fewer pairs of legs upon hatching. There may be five or more immature stages with the number of legs increasing with each molt.
These arthropods are able to survive both inside and out, but prefer to move indoors when outside temperatures become unfavorable. Only the house centipede has been known to inhabit buildings year round where they feed primarily on spiders and cockroaches. Stone and soil centipedes are able to enter buildings through expansion cracks, through floor drains and around plumbing fixtures, as well as other small imperfections in the structure. They hide under cardboard, baseboards and in other damp, cool areas of the house. Most stone and soil centipedes die rather rapidly inside dry buildings.
Generally, centipedes do not occur in large numbers indoors, and are actually considered beneficial because they capture spiders and other house-dwelling arthropods. Large numbers of centipedes indoors may indicate that other arthropods used for food are in high numbers. By monitoring with sticky traps, you can observe which and how many arthropods are present in your home.
Removing harborage is one of the key components in reducing centipede numbers in and around your home. Keep old boards, rotting wood, compost piles, grass clippings, leaves, stones, etc., away from the house foundation. If practical, remove trash or leaf litter in a strip three feet wide surrounding the house foundation, allowing the soil surface to be exposed to air and sunlight. Maintain foundation expansion joints and seal around lower windows and doors. Inspect for cracks and crevices in foundation walls and use sealants to block these potential entry points.
Properly ventilate basements and subfloor crawlspaces to eliminate excess moisture. A dehumidifier may be useful. Indoors, control nuisance insect populations to reduce the food source (prey) of centipedes. Centipedes can be collected by broom and dustpan, vacuum cleaner or other mechanical means and discarded.
Most centipedes are susceptible to commonly used insecticides. Sticky traps can be used to determine if you have a centipede problem. Try to determine where the centipedes are coming in and first try to seal the entrance place. If necessary, apply a preventive barrier of insecticide in a band (18–36 inches) around the foundation of the house or building. This is called a perimeter application. Granular formulations often seem to provide longer residual activity than sprays. If the label allows, repeat applications at intervals (14–28 days is often recommended) listed on the instructions. Indoor spot treatments are generally not required or recommended. Total release aerosols (so-called "bug bombs") are also ineffective against centipedes as these products do not leave behind any active residues and they rarely reach the cracks or crevices where centipedes are hiding. Always read the label and follow directions and safety precautions.
This fact sheet is a revision of HYG-2067.