Minnesota is home to a small number of centipede species, and the one you’re most likely to encounter indoors is the house centipede. These fast-moving, long-legged arthropods look alarming but are harmless to people and actually help control other household pests. If you’ve spotted one scurrying across your basement floor, here’s what you’re dealing with and what to do about it.
Species Found in Minnesota
Two centipede types show up regularly in and around Minnesota homes: the house centipede and the stone centipede.
The house centipede is the one that startles people. Fully grown, it’s over an inch long with a flattened, brownish or grayish-yellow body sometimes marked with three dark stripes down its back. Its most distinctive feature is 15 pairs of long, jointed, striped legs that fan outward, giving it an almost feathery appearance. Two long, slender antennae extend from the head. Those legs make it remarkably fast, which is part of why an encounter in a dark hallway feels so unsettling.
The stone centipede is an outdoor species you’ll find under mulch, leaf litter, loose bark, and rocks. It can reach about two inches long and spends its time hunting insects, spiders, and other small creatures on the soil surface. Stone centipedes are harmless to people and rarely make their way inside.
What They Eat (and Why That Matters)
House centipedes are active predators. They hunt silverfish, carpet beetle larvae, cockroaches, spiders, ants, and other small arthropods. That diet makes them genuinely useful, even if you’d rather not share your bathroom with one.
Here’s the more important takeaway: if you’re seeing house centipedes frequently, they’re there because they have a reliable food supply. Their presence in large numbers usually signals an underlying pest problem. The centipedes are a symptom, not the root issue. Something else in your home, whether it’s silverfish in the attic or carpet beetles in the closet, is feeding them.
Are Centipede Bites Dangerous?
Centipedes do have venom, which they use to subdue their insect prey. In theory, a house centipede could bite a person, but it rarely happens. Their jaws are small and often can’t penetrate human skin effectively. When a bite does occur, it typically causes localized pain, some swelling, and minor redness that resolves within a few days without treatment. Think of it as roughly comparable to a bee sting in severity.
Serious reactions are extremely rare. In medical literature, severe complications from centipede bites (allergic reactions, significant drops in blood pressure) have been documented, but these cases almost always involve large tropical species, not the small centipedes found in Minnesota. The clinical course for bites from house centipedes and stone centipedes is benign and self-limited.
Centipedes vs. Millipedes
Both show up in Minnesota basements, and people often confuse them. A few quick differences:
- Body shape: Centipedes have a flattened body. Millipedes are rounded and more cylindrical, with a harder shell.
- Legs per segment: Centipedes have one pair of legs per body segment. Millipedes have two pairs per segment, giving them a denser, rippling leg pattern.
- Movement: Centipedes are fast and darting. Millipedes move slowly and tend to curl into a spiral when disturbed.
- Diet: Centipedes are predators that eat other insects. Millipedes feed on decaying plant material and leaf litter.
- Antennae: Centipedes have long, prominent antennae. Millipedes have a pair of short, stubby ones.
If what you found is slow, round-bodied, and curls up when touched, it’s a millipede. If it’s flat, fast, and has visibly long legs, it’s a centipede.
Why They Come Inside
Centipedes need moisture to survive. They lack the waxy outer coating that many insects have to retain water, so they dry out quickly in low-humidity environments. This is why you almost always find them in basements, bathrooms, crawl spaces, and laundry rooms. Minnesota’s cold winters drive them toward the warmth and dampness of heated homes, particularly older ones with stone foundations or unfinished basements where humidity tends to be higher.
They get in through cracks in foundations, gaps around windows, spaces under doors, and openings where utility lines enter the house. Once inside, a damp basement with a healthy population of spiders or silverfish is everything a house centipede needs to set up permanently.
How to Reduce Centipede Activity
Because centipedes follow moisture and food, the most effective approach targets both.
Lower Indoor Humidity
Run a dehumidifier in your basement, especially during the humid summer months when Minnesota’s dew points climb. Fix leaky pipes and faucets. Improve ventilation in bathrooms and crawl spaces. If you make the environment dry enough, centipedes simply can’t sustain themselves there.
Cut Off Their Food Supply
This is the step most people skip. Reducing the centipede population means reducing whatever they’re eating. Place sticky insect traps (sometimes called monitors) around your basement and other damp areas. After a week or two, check what you’ve caught. That tells you what pest is actually drawing centipedes in, whether it’s silverfish, carpet beetles, or something else, and lets you address the real problem.
Keep kitchens clean, vacuum regularly, and reduce clutter. Stacks of boxes, piles of newspapers, and cluttered storage areas create exactly the kind of dark, undisturbed hiding spots that both centipedes and their prey prefer.
Seal Entry Points
Inspect your foundation for cracks and fill them with caulk or expanding foam. Check the seals around basement windows, install door sweeps on exterior doors, and close gaps where pipes or wiring enter the house. This won’t stop every centipede, but it significantly reduces the number finding their way in from the soil and leaf litter outside.
For outdoor control, pull mulch, leaf piles, and stacked firewood away from your foundation. Stone centipedes live in exactly those materials, and keeping them a few feet from the house creates a buffer zone that makes indoor entry less likely.