Philadelphia Centipede & Millipede Infestation — Reading the Underlying Cause
Centipedes and millipedes are not random visitors in Philadelphia homes — they are indicators. High moisture in crawlspaces or basements, organic debris close to the structure, and insect populations in wall voids or lower floors all attract these arthropods reliably. Treating the population without addressing these conditions produces only temporary results.
Millipedes feed on decomposing plant matter and are driven indoors when soil becomes saturated — typically after sustained rainfall or autumn wet periods. They enter through foundation gaps, door thresholds, and utility penetrations, often appearing in large numbers overnight. Centipedes enter separately, following the insect prey populations that live in the same damp conditions.
Identifying Which Species You Have in Philadelphia
Centipedes are fast-moving predators with one pair of legs per body segment. The house centipede can deliver a mild bite if handled. Millipedes are slow-moving detritivores with two pairs of legs per segment. They do not bite but produce defensive secretions that cause skin irritation in some people.
Treatment Approach in Philadelphia
Effective control requires both chemical treatment and environmental modification. Perimeter spray reduces the population entering the structure, while moisture and harborage reduction addresses the conditions sustaining the population.