Two Different Animals
House Centipede
The house centipede (Scutigera coleoptrata) is the fast-moving, many-legged predator that surprises homeowners in bathrooms and basements. Up to 1.5 inches long with 15 pairs of legs that extend well beyond the body, they are visually alarming but genuinely beneficial — house centipedes are active hunters of other household pests including silverfish, firebrats, cockroaches, and spiders. They require high humidity and will not persist in structures with adequately controlled moisture. A house centipede indoors means the humidity and likely the prey insects that sustain them are present.
Millipedes
Millipedes are slow-moving decomposers — they feed on decaying plant material in moist soil and leaf litter outdoors. Missouri's most common structural invader is the flat-backed millipede and the North American millipede, both of which migrate into structures in fall as temperatures drop or during wet weather events that saturate outdoor habitat. Millipede migrations into basements through foundation gaps, crawlspace vents, and door thresholds can be substantial — dozens to hundreds in a single night during peak migration conditions. They die quickly indoors due to low humidity and do not reproduce in structures.
Control Approach — Both Species
- Reduce exterior moisture: pull mulch and leaf litter back from the foundation, improve drainage in foundation planting beds
- Seal entry points: foundation cracks, crawlspace vent screens, door threshold gaps where millipedes enter in mass migrations
- Address crawlspace moisture: vapor barrier and ventilation management reduces the humidity that sustains centipede prey and attracts millipedes
- Perimeter residual treatment during fall migration periods reduces millipede entry significantly
D&D Pest Control provides moisture pest management for Franklin County and rural Missouri — visit ddpestcontrolmo.com.