Household Millipedes — Why They’re in Your Home & What to Do About It
If you’ve walked into your basement or laundry room and found dozens of small, dark, segmented creatures curled up in tight spirals on the floor, you’ve met household millipedes. At Northwest, we get a sharp spike in millipede calls every spring and fall across Georgia and Alabama. The cycle is predictable: heavy rain saturates the outdoor environment where millipedes normally live, they move toward drier ground, and suddenly your basement or crawl space becomes the most appealing real estate in the county.
The good news: household millipedes are completely harmless. They don’t bite, they don’t sting, and they don’t carry disease. The less-good news: when they show up indoors, they usually show up in numbers. Here’s why they end up in Southeast homes, how to tell a millipede from a centipede (a common confusion), and what to do about an active indoor invasion.
What Are Household Millipedes?
Household millipedes are elongated, segmented arthropods with two pairs of legs per body segment. Despite the name (which translates to “thousand feet”), most species have between 80 and 400 legs. They’re typically dark brown to black, about 1 to 1.5 inches long when fully grown, and roll into a tight spiral when threatened.
Three things to know about millipede biology:
- Diet: Millipedes are detritivores. They eat decaying plant matter, leaf litter, rotting wood, and damp organic material. They don’t eat live plants, fabric, food in your pantry, or anything else inside a house.
- Habitat: They need moisture to survive. Outdoors, that means mulch beds, leaf litter, decaying logs, under stones, and the top layer of soil. Indoors, they’re drawn to basements, crawl spaces, bathrooms, and laundry rooms.
- Lifespan: Most species live 1 to 2 years. They’re slow movers, slow reproducers, and not aggressive in any way.
Millipedes vs Centipedes (Don’t Confuse Them)
This is the single most common identification mistake we see homeowners make on millipede calls. The two creatures look superficially similar but behave very differently.
Millipedes are slow, harmless plant-matter eaters. Centipedes are fast, predatory, and can deliver a painful bite.
Quick reference for distinguishing millipedes from centipedes:
| Feature | Millipede | Centipede |
|---|---|---|
| Legs per body segment | 2 pairs (4 legs) | 1 pair (2 legs) |
| Body shape | Round, tube-like, segmented | Flat, more ribbon-like |
| Speed | Slow, deliberate movement | Fast, darting movement |
| Diet | Decaying plant matter | Other insects and small invertebrates |
| Defense | Curls into a tight spiral | Runs away, can deliver a mild bite |
| Danger to humans | None | Bite can sting, similar to a bee |
If you found something moving slowly, curled up when you got close, and looks tube-shaped, it’s almost certainly a millipede. If something darted away fast on flat legs, it was a centipede. Both can show up in the same conditions (damp basements, leaf litter), but treatment and concern levels differ. For the broader category of misunderstood “creepy” household pests, see our granddaddy long legs guide, which covers another commonly feared but harmless household visitor.
Why Are There So Many Household Millipedes in Your House?
Millipedes don’t choose to be indoors. They end up in homes because the conditions outside become inhospitable and your basement, crawl space, or laundry room offers what they need: moisture and shelter. Four conditions reliably push millipedes indoors in the Southeast:
Heavy Rain or Saturated Soil
The most common trigger for a sudden millipede invasion is a heavy spring or fall rainstorm. When soil becomes waterlogged, millipedes move to higher ground. If “higher ground” is the dry concrete of your basement floor, that’s where they go. We see millipede calls spike within 48 hours of major rain events across Georgia, Alabama, and Tennessee.
Drought or Extreme Dryness
The opposite condition triggers a similar response. During extended dry periods, outdoor environments become too dry for millipedes to survive. They migrate toward any source of moisture, which often means crawling under doors, through foundation cracks, or up basement window wells to find indoor humidity.
Yard Conditions Around the Foundation
Yards that hold moisture against the house make millipede invasions more likely. The biggest contributing factors:
- Heavy mulch beds within 3 feet of the foundation (especially wood chip mulch)
- Leaf litter that accumulates against the house
- Decorative stones or wood timbers laid directly on soil
- Irrigation systems that spray foundation walls
- Downspouts that empty within 2 feet of the foundation
- Stacked firewood, lumber, or yard debris near the house
Indoor Moisture and Cracks
Millipedes can’t enter a house without an opening, and they can’t survive indoors long without humidity. Both have to be present. Common entry points:
- Foundation cracks at grade level
- Gaps under exterior doors (especially garage side doors and basement hatches)
- Unsealed crawl space vents
- Window wells with cracked or missing covers
- Gaps around utility line penetrations
- Weep holes in brick veneer that aren’t screened
Indoor conditions that let them stick around once inside: damp basements, leaking pipes, condensation on cold water lines, poor ventilation in crawl spaces, and standing water in floor drains.
Signs of a Millipede Presence
Most homeowners notice millipedes because they see them directly. Other signs to watch for:
- Live sightings on basement or crawl space floors, especially after rain or in early morning hours.
- Curled-up “dead” millipedes in dry indoor environments — the spiral defense posture also happens when they die from dehydration indoors. Finding several curled millipedes in a basement corner is a sign that more are entering and dying.
- Movement after rain. If you see a single millipede the day after a thunderstorm, you’ll probably see more over the next 48 hours.
- Clusters near damp areas like basements, laundry rooms, bathrooms, and crawl space access points.
- Shed exoskeletons in undisturbed corners, which suggests an established indoor population rather than just visitors.
Are Household Millipedes Harmful?
No. Household millipedes do not bite, sting, transmit disease, damage structures, contaminate food, or harm pets. They are completely harmless to humans and pets.
Three small caveats:
- Defensive secretions. Some millipede species release a mild liquid when handled or threatened. The secretion can stain skin briefly and irritate eyes if rubbed in. Wash hands after handling any millipede. Don’t let pets eat them in large numbers — the secretion can cause mild mouth irritation in dogs and cats.
- Allergic reactions. A small percentage of people have allergic skin reactions to millipede secretions. Reactions are mild (redness, itching) and resolve quickly.
- Dead millipede smell. Large numbers of dead millipedes in basement corners can develop a faint, unpleasant odor as they dry out. Vacuum them up promptly.
The UGA Extension Bulletin B 1412 on Southeastern household pests classifies millipedes as a “nuisance pest” — uncomfortable to encounter but not harmful.
How to Prevent Household Millipedes
The most effective millipede prevention works on three fronts: outdoor conditions, entry points, and indoor moisture.
A 3-foot mulch-free zone around the foundation is the single highest-impact millipede prevention move for most Southeast homes.
Outdoor Conditions
- Keep mulch beds at least 3 feet from the foundation. If you have mulch right against the house, that’s the single biggest contributor to millipede invasions. Replace the foundation perimeter with gravel, river rock, or bare soil.
- Remove leaf litter from the foundation line. Rake regularly during fall and after storms.
- Move firewood, lumber, and debris piles at least 20 feet from the house.
- Direct downspouts and irrigation away from the foundation. Pooling water within 2 feet of the house is millipede paradise.
- Trim shrubs back so air can circulate against the foundation. Damp, shaded foundation walls hold millipedes longer.
Seal Entry Points
- Caulk foundation cracks at ground level.
- Install or replace door sweeps and weatherstripping, especially on garage doors and basement hatches.
- Screen crawl space vents with galvanized 1/4-inch hardware cloth.
- Cover window wells with rigid plastic or metal covers.
- Seal gaps around utility line penetrations with steel wool and caulk.
Indoor Moisture Control
- Fix leaky pipes promptly. Even small leaks support indoor millipede populations.
- Run a dehumidifier in basements and crawl spaces.
- Improve ventilation in bathrooms and laundry rooms.
- Don’t store cardboard boxes directly on damp basement floors.
How to Get Rid of Household Millipedes
Once millipedes are already inside, the treatment approach is straightforward.
DIY Methods
- Vacuum them up. A regular vacuum with a hose attachment handles individual millipedes quickly. Empty the canister or bag outside afterward.
- Sweep into a dustpan. Slower but works for small numbers.
- Reduce indoor humidity. A dehumidifier in active areas often resolves an indoor population within a few weeks. Without moisture, millipedes can’t survive indoors.
- Skip insecticide sprays. Indoor sprays don’t work well on millipedes because they don’t stay in one place long enough to absorb the active ingredients. Sprays also leave residue that’s unnecessary for a harmless pest.
For ongoing prevention while you address the conditions, see our companion guide on natural ways to remove and prevent millipedes in your house.
When to Call Northwest
Most millipede problems clear up once you fix the outdoor conditions and seal the entry points. Call us if:
- Indoor sightings continue for more than 2 weeks despite your prevention efforts.
- You’re finding more than 10 to 15 millipedes per day in any single room.
- You can’t identify the entry points and want a professional inspection.
- You’re dealing with millipedes plus another pest (centipedes, sowbugs, springtails). All share the same moisture-driven entry pattern and can be solved together.
(Persistent millipede problem? Schedule a free Northwest inspection and we’ll find the entry points and address the moisture issues driving them indoors.)
Household Millipedes & Local Environmental Factors
Millipede pressure in Georgia, Alabama, Tennessee, and South Carolina is consistently higher than in drier or colder regions. Three Southeast-specific factors:
- Humidity. Long humid summers create constant indoor and outdoor moisture, which sustains millipede populations year-round.
- Heavy spring and fall rains. The Southeast’s two rainy seasons drive the two annual peaks in indoor millipede sightings.
- Construction patterns. Many Southeast homes have crawl spaces and slab additions with foundation features (cracks, vents, soffit gaps) that are reliable millipede entry points.
The good news: the conditions that attract millipedes also attract other “moisture pests” (sowbugs, springtails, centipedes, sometimes ground beetles). Fixing the conditions for millipedes generally fixes the conditions for all of them at once.
Frequently Asked Questions About Household Millipedes
Do millipedes bite?
No, household millipedes do not bite humans or pets. They have no biting mouthparts capable of penetrating skin. Some species release a mild defensive secretion when handled, which can briefly irritate sensitive skin. Wash hands after handling.
Are millipedes attracted to lights?
Not typically. Unlike many flying insects, millipedes don’t navigate by light. They’re drawn to moisture, organic matter, and dark sheltered spaces. If you’re seeing them near lights, it’s usually because the lighted area happens to have moisture or shelter nearby, not because of the light itself.
Will household millipedes go away on their own?
They can. If the outdoor conditions that drove them indoors change (rain stops, drought ends, mulch dries out), most millipedes will leave or die from dehydration within a few days. However, large indoor populations or homes with persistent moisture issues usually need active intervention to fully clear.
How long do household millipedes live?
Most household millipede species live 1 to 2 years in the wild. Indoors, they typically don’t survive long without consistent moisture access. The “dead millipede” curls you find in dry basement corners are often individuals that entered seeking moisture and dehydrated before finding any.
What’s the difference between a household millipede and a centipede?
Millipedes have 2 pairs of legs per body segment, move slowly, eat decaying plant matter, and curl into a spiral when threatened. Centipedes have 1 pair of legs per body segment, move fast, are predatory (they eat other insects), and can deliver a mildly painful bite. Both can show up indoors in similar conditions, but only centipedes warrant any caution.
Most millipede problems get solved by fixing the outdoor conditions and sealing the entry points — not by spraying inside.
Stop the Millipede Problem at the Source
If household millipedes keep showing up in your basement, laundry room, or crawl space, the answer almost always lies outside the house. Northwest’s team handles the full millipede workflow: identifying the moisture and entry-point conditions driving them in, sealing the access points, and addressing any underlying drainage or humidity issues. Most homeowners are surprised how much of the work happens around the foundation rather than inside.
- Schedule a Free Pest Inspection
- Learn About Our Pest Control Services
- Call (888) 466-7849. Same-week service available across our Southeast service area.