Philadelphia Centipede & Millipede Infestation — Reading the Underlying Cause
House centipedes and millipedes are moisture-dependent arthropods that are rarely present in significant numbers unless the conditions supporting them are well established. In Philadelphia homes, their presence typically indicates excess moisture in basements or crawlspaces, accumulation of organic debris outdoors, or an underlying insect population (house centipedes prey on other insects).
Millipedes, which feed on decaying organic matter, often invade in large numbers after heavy rainfall — migrating from outdoor mulch and leaf litter into foundations and through gaps in the building envelope. Centipedes follow the insects they feed on.
Identifying Which Species You Have in Philadelphia
Centipede: fast-moving, flat-bodied, one leg pair per segment, predatory. House centipedes are drawn indoors by insect prey and can deliver a mild bite if handled directly. Millipede: slow-moving, cylindrical, two leg pairs per segment, feeds on decomposing organic material. Millipedes coil defensively when disturbed and secrete compounds that cause skin and eye irritation in sensitive individuals — handle neither species without protection.
Our Integrated Treatment Approach for Philadelphia Properties
Our Philadelphia treatment approach runs on two tracks simultaneously. Residual perimeter treatment and interior application reduce the active population. Moisture assessment, entry point sealing, and harborage reduction advice remove the underlying conditions — so the same problem does not return with the next wet season.