Telling a house centipede from a millipede comes down to three things: leg count, speed and diet. Centipedes carry one long pair of legs per body segment and hunt other insects, while millipedes carry two short pairs per segment, move slowly, and feed mostly on decaying matter instead of live prey.
Difference Between House Centipede and Millipede: Legs and Body Shape
Counting legs per segment is the fastest way to tell them apart. A house centipede grows one pair of long, thin legs on each body segment, and those legs splay out visibly from a flattened frame. A millipede carries two pairs of short legs per segment instead, which gives it a rounder, tube-shaped body that reads more like an armoured worm.
Colour reinforces the shape difference. Centipedes tend toward yellow or reddish brown with flatter frames, while millipedes run pale grey through near-black and keep a thicker, rounded profile as they mature. The house centipede species found in Ontario homes also has unusually long antennae and a stretched-out rear leg pair, both oversized relative to its body.
Difference Between House Centipede and Millipede: Speed and Behaviour
Movement style backs up whatever the leg count already told you. A house centipede covers ground in quick, jerky sprints and stops dead the instant a light flicks on or a floorboard shifts. A millipede instead ripples forward slowly and, when startled, rolls its whole body into a tight coil rather than trying to escape.
- Fast, erratic movement across floors or tile: house centipede.
- Slow, steady crawl with a wave-like leg motion: millipede.
- Coils into a flat spiral when touched: millipede.
- Never coils, instead freezes or sprints for cover: house centipede.
| House Centipede | Millipede | |
|---|---|---|
| Legs per body segment | One long pair | Two short pairs |
| Typical speed | Fast, darting bursts | Slow, wave-like crawl |
| When disturbed | Runs or freezes, never coils | Coils into a tight spiral |
| Primary diet | Other small insects (predator) | Decaying plant matter (scavenger) |
| Where usually found indoors | Damp basements, bathrooms, humid utility rooms | Rare indoors, usually near entry points after wet weather |
Centipede or Millipede in My House? What Each One Means
Finding a centipede or a millipede indoors points to two completely different situations. Millipedes scavenge outdoors and only wander in during rainy stretches or heavy mulching season; once inside, they typically dry out and die within a few days because there is no soil-based food source to sustain them. A house centipede behaves differently because it hunts, and hunters only hang around where enough prey exists to feed them.
A house centipede that keeps turning up indoors is not a coincidence. It signals that silverfish, drain flies, small ants or other soft-bodied insects are already established somewhere in the home, and the centipede is simply tracking that food supply.
Why House Centipedes Turn Up in Ontario Basements
House centipedes have no waterproof coating on their exoskeleton, so dry air pulls moisture out of their bodies fast. That one limitation explains most of their favourite hiding spots: basements, bathrooms, laundry rooms and any other area holding more humidity than the rest of the house. A dry, well-ventilated room simply cannot support them for long.
They get indoors through the same small openings their prey uses first, including foundation cracks, gaps around pipes and utility lines, loose window frames and window well seams. A basement that stays damp over time is rarely just a centipede nuisance; it usually signals both a moisture problem and an entry point that is feeding the insects the centipedes are hunting.
What to Do When You Spot One
Identify it first
Count the leg pairs per segment and watch how it moves. A fast, darting run with one long leg pair per segment points to a house centipede; a slow crawl with two short leg pairs and a coiling reaction points to a millipede.
Check for a prey signal
Scan the area for silverfish, small ants, drain flies or other soft-bodied insects. A house centipede sighting usually means one of these populations is already active somewhere in the home.
Check moisture in the area
Note whether the room feels damp, shows condensation, or hints at a slow leak. Both centipedes and the prey they chase depend on indoor humidity to survive.
Call a licensed technician if sightings continue
Sightings that persist over more than a week or two signal an established prey population and an entry point problem that DIY measures alone rarely fix.
What Repeated Sightings Are Really Telling You
Spotting a single centipede crossing the basement floor once isn't alarming. Several sightings within a week is different and usually means a steady prey population is being fed by a steady moisture source. Silverfish follow the same pattern: one or two a month is unremarkable, but several in a single week often traces back to a slow leak hiding behind tile, under a vanity, or inside a wall cavity.
Log the date of each centipede sighting in the same room. A pattern that builds over two or three weeks tells you far more about the underlying moisture and prey issue than any one-off appearance does.
Are House Centipedes Dangerous to People or Pets?
House centipedes pose no meaningful health risk to people or pets. They subdue prey with modified front legs called forcipules instead of jaws, and the venom delivered through them is scaled for small insects, not larger animals. The house centipede species common across Canada almost never has the bite force to break human or pet skin, so an actual bite is rare even with direct handling.
They sit in the same low-risk category as most household spiders. House spiders, cellar spiders and wolf spiders make up the bulk of spider sightings in Ontario homes, and none of them carry meaningful health risk either, which puts centipedes and typical indoor spiders on equal footing as low-concern finds.
DIY Steps That Help Between Professional Visits
A few practical steps can support professional treatment or hold activity down while waiting for it:
- Dust a light layer of diatomaceous earth into cracks and crevices along centipede and insect travel routes; it scrapes away the protective coating on small insects and dries them out.
- Place boric acid along the same routes; prey insects that ingest it suffer internal nervous system and stomach damage, which shrinks the food source centipedes rely on.
- Run a dehumidifier or boost ventilation in basements and bathrooms to cut the humidity both centipedes and their prey need to survive.
- Log sightings by room and date instead of reacting to any single appearance.
Over-the-counter baseboard sprays only kill on contact and leave both the moisture issue and the underlying insect population untouched, so activity tends to reappear within a couple of weeks. A licensed treatment typically pairs an exterior perimeter application with interior spray and dust work inside accessible wall voids, targeting the centipedes and the prey insects sustaining them rather than relying on contact spray alone.
How to Tell Centipedes and Millipedes Apart in One Look
With limited time, three checks settle it almost every time: count the leg pairs per segment, watch whether it runs or ripples, and see if it coils when nudged. A flat, fast-moving animal with one leg pair per segment that never coils is a house centipede. A slower, rounder animal with two leg pairs per segment that curls into a spiral is a millipede.
How AstraHive Pest Control gets rid of centipedes
Centipedes come in from damp ground and follow the insects in your house, so we treat the edge of the building where they enter and look for what is feeding them.
How an AstraHive centipedes treatment works
Inspect first
We inspect the foundation, slab cracks, floor drains, crawl spaces and basement corners for centipedes, moisture and the insects and spiders they prey on.
Treat where it counts
We apply a residual treatment to the exterior perimeter that stays active for about 90 days, according to the product label, and we point out the damp spots and gaps to fix.
Treat inside only when needed
If a large number of centipedes or their prey are already inside, we add an interior treatment and dust into wall voids. A single house centipede does not need one.
Back it with a 90-day warranty
If centipedes come back within 90 days, we re-treat at no charge.
We also dust into the accessible wall voids and cracks where these insects travel and hide, with a professional dust that keeps working in places a spray cannot reach. That, together with the outside treatment, is how we keep them from coming back, rather than trying to seal every gap, because insects find another way in.
Our products are Health Canada approved and safe for kids and pets, and we apply every product according to its label. AstraHive is licensed by the Ontario Ministry of the Environment, Conservation and Parks. Ontario requires a ministry-approved certification course before it issues an exterminator licence, and that training is delivered through the University of Guelph, Ridgetown Campus.
Why Choose AstraHive
- Licensed & Insured: Certified by the Ontario Ministry of Environment, Conservation and Parks.
- Fast response: Same-day service available, with a callback within 5 minutes.
- 90-Day Warranty: If pests come back within that window, we re-treat at no additional charge.
- Proven track record: 5.0 stars on Google across 200+ reviews.
- Family & pet safe: Health Canada approved products on every job.
Frequently Asked Questions
What is the difference between house centipede and millipede?
A house centipede has one pair of long legs per body segment, moves fast and hunts other insects, while a millipede has two pairs of short legs per segment, moves slowly and feeds on decaying plant matter. Body shape differs too: centipedes are flatter and millipedes are rounder.
How can I tell centipedes and millipedes apart quickly?
Watch the speed and the reaction to being disturbed. A fast animal that never curls up is a centipede, while a slow animal that coils into a tight spiral when touched is a millipede.
Does a centipede or millipede in my house mean I have an infestation?
A millipede indoors is usually a one-off wanderer from outside that dries out within days. A house centipede seen repeatedly is more significant, since it is a predator that only stays where there is enough prey, such as silverfish or small ants, to sustain it.
Are house centipedes dangerous to pets?
House centipedes are not considered dangerous to pets. Their venom is intended for small insect prey, and the species found in Canadian homes rarely has the jaw strength to break skin, so bites to pets are uncommon and generally minor if they occur.
Do millipedes bite like centipedes do?
No. Millipedes have no venom delivery system and do not bite; some species release a mild irritating fluid if handled roughly, but this is a defensive secretion rather than a bite. Centipedes, by contrast, use modified front legs to inject venom into prey, though this rarely affects humans or pets.
Sources
- Health Canada: Centipedes, millipedes, sowbugs and pillbugs (Pest control tips) — House centipedes are 2.5 to 5 cm with 15 pairs of legs; they invade when sub-floor, drains, basement or bathroom are damp and come indoors in fall; they eat spiders, bed bugs, cockroaches, silverfish, carpet beetles and ants; most cannot pierce skin; slope the ground away, clear leaf litter, use a dehumidifier.
- Ontario Ministry of Agriculture, Food and Rural Affairs (ontario.ca) — Centipedes are usually yellow to reddish brown with flatter bodies than millipedes, have only one pair of legs per body segment, and their legs are generally longer and stick out along the sides of the body, while millipedes coil into a tight spiral when disturbed.
- Ontario.ca: Pesticide licences and permits — Ontario's Ministry of the Environment, Conservation and Parks issues exterminator licences after a ministry-approved certification course, delivered through the University of Guelph, Ridgetown Campus.
- National Capital Poison Center (poison.org) — Centipedes use a pair of modified hollow front legs called forcipules, rather than jaws, to catch prey and deliver venom, and the house centipede group (genus Scutigera) is relatively harmless to people.
- UC Statewide Integrated Pest Management Program, University of California — Centipedes never coil up when disturbed, unlike millipedes, and the house centipede species that invades buildings has unusually long legs that let it run rapidly compared with garden centipede species.
- House Digest — Millipedes have rounded, earthworm-like bodies with two leg pairs per segment, while centipedes have flatter bodies with only one pair of legs per segment and are known for greater speed despite having fewer legs overall.
Areas We Serve
AstraHive Pest Control proudly serves 75+ communities across the following regions:
- Toronto: Toronto, North York, Scarborough, Etobicoke, East York, York, Leslieville, Lakeview
- Durham Region: Oshawa, Whitby, Ajax, Pickering, Clarington, Bowmanville, Courtice, Newcastle, Port Perry, Brooklin, Uxbridge, Scugog, Brock, Seaton
- York Region: Vaughan, Markham, Richmond Hill, Aurora, Newmarket, Thornhill, Woodbridge, Kleinburg, Maple, Stouffville, Unionville, Keswick, Holland Landing, East Gwillimbury, Georgina, King City, King Township, Nobleton, Berczy Village, Cathedraltown, Commerce Valley, Cornell, Wismer, Whitchurch-Stouffville, Sutton, Schomberg
- Peel Region: Mississauga, Brampton, Caledon, Malton, Port Credit, Streetsville, Meadowvale, Cooksville, Bolton, Palgrave
- Extended Service Area: Peterborough, Lindsay, Port Hope, Barrie, Bradford, Innisfil, Collingwood, Wasaga Beach, Orillia, Burlington, Oakville, Milton, Hamilton, Grimsby, St. Catharines, Welland, Niagara Falls
Don't see your city listed? Call us — we likely cover it.
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