Centipedes and millipedes are often lumped together, but they're different creatures with different habits — and knowing which you have makes them easier to control. Both are "occasional invaders" drawn indoors by moisture.
Telling Centipedes and Millipedes Apart
Centipedes have one pair of legs per body segment, move fast, and are predators — they hunt other insects. Millipedes have two pairs of legs per segment, move slowly, curl into a coil when disturbed, and feed on decaying plant matter. Centipedes are the ones that dart across the bathroom floor; millipedes are the slow, cylindrical ones you find in damp basements or after heavy rain.
Why They Get Into Your Home
Both need moisture to survive, so they gather in damp areas — basements, crawl spaces, bathrooms, under sinks, and around foundations. They wander indoors when it's too wet outside (after rain) or too dry, and slip in through foundation cracks, gaps around pipes, and door thresholds.
Are They Dangerous?
Mostly no. Millipedes don't bite; some release a mild defensive fluid that can irritate skin, so wash your hands after handling one. Larger centipedes can deliver a bite that stings like a bee sting if handled, but they're not dangerous to most people and they actually eat other household pests. Neither carries disease.
How to Get Rid of Them
Because both are moisture-driven, control starts with drying things out: run a dehumidifier, fix leaks, improve crawl-space ventilation, and clear damp leaf litter and mulch away from the foundation. Seal entry points, and a professional treatment around the foundation and interior harborage areas eliminates the ones inside and deters more from entering.
Frequently Asked Questions
Centipedes have one pair of legs per segment, move fast, and hunt insects; millipedes have two pairs per segment, move slowly, curl up when disturbed, and eat decaying plant matter.
Generally no. Millipedes don't bite (though their defensive fluid can irritate skin); large centipedes can bite if handled, stinging like a bee sting, but neither is dangerous to most people or carries disease.
Both are drawn to moisture and enter from damp areas around the foundation through cracks and gaps, especially after heavy rain or during dry spells. Damp basements, crawl spaces, and bathrooms are common spots.
Reduce moisture (dehumidifier, fix leaks, ventilate crawl spaces), clear damp mulch and leaf litter from the foundation, seal cracks and gaps, and use a professional perimeter treatment.