Centipedes are predatory arthropods with elongated, segmented bodies and a single pair of legs on most segments, belonging to the class Chilopoda. The sight of a centipede, particularly the quick-moving house centipede (Scutigera coleoptrata), often sparks immediate alarm due to its numerous legs and speed. Whether these creatures are beneficial or harmful depends on the specific environment and the priorities of the human occupants.
The Centipede’s Role as a Beneficial Predator
Centipedes are generalist carnivores, making them beneficial in controlling pest populations. They are nocturnal hunters that use their speed and venom to capture and subdue other small arthropods. These arthropods are drawn to homes because an existing pest problem provides an enticing food source.
The house centipede, in particular, is a natural exterminator that feeds on many common household invaders. Their diet includes insects like silverfish, cockroaches, crickets, flies, spiders, and fly larvae.
The presence of centipedes can indicate a larger underlying issue: an abundance of their prey. While their predation may only marginally reduce large infestations, it provides a degree of biological control that homeowners may not even notice.
Understanding Centipede Bites and Venom
Centipedes possess a pair of modified front legs called forcipules, which function as pincer-like appendages to inject venom. These forcipules are located near the head and are used to subdue prey or for defense. All centipedes are venomous, but the medical significance to humans varies greatly by species.
For the common house centipede, the bite is generally not medically serious and is often compared to a bee sting in terms of pain. Smaller species may not even be able to puncture human skin. Typical localized symptoms include pain, redness (erythema), and swelling (edema) at the bite site, which usually subside within a few hours to a couple of days.
More severe symptoms, such as headache, nausea, or irregular pulse rates, are uncommon and usually associated with bites from larger species or with individuals who have a higher sensitivity or allergy to the venom. Anaphylaxis from a centipede bite is extremely rare but possible for allergic individuals. If a bite occurs, cleaning the area with soap and water and applying a cold compress is standard first aid.
Why Centipedes Enter Human Structures
Centipedes are especially susceptible to water loss because they lack the waxy outer layer found on many insects and arachnids. They must seek out dark, cool, and damp environments to avoid dehydration. Outdoors, they thrive under rocks, logs, leaf piles, and other moist debris.
When environmental conditions outside become too dry or cold, or when their prey moves indoors, centipedes follow the available moisture and food sources into human structures. They enter homes through small openings, such as:
- Tiny cracks in the foundation.
- Loose siding.
- Unsealed windows.
- Gaps around pipes.
Once inside, they gravitate toward humid areas such as basements, crawl spaces, bathrooms, and laundry rooms. The house centipede is often seen because it is more adapted to living its entire life cycle indoors, especially in areas with persistent moisture issues. Reducing excess moisture inside a home with a dehumidifier and sealing entry points can make the environment less appealing to them.