Centipedes in Your BC Basement: Why They’re There and How to Get Rid of Them
You flip on the basement light and something moves — fast. A pale, many-legged creature darts across the floor and disappears behind a storage box before you can process what you saw. If you’re a BC homeowner, especially in the Lower Mainland, you’ve probably had this unsettling experience. Centipedes in your basement are one of the most common — and most startling — pest encounters in our region.
The good news is that house centipedes aren’t the nightmare they appear to be. The better news is that once you understand why they’re in your basement, getting rid of them is straightforward. Here’s your complete guide to centipedes in BC basements — from identification to elimination.
Identifying House Centipedes in BC
The species you’re almost certainly encountering is the house centipede (Scutigera coleoptrata), and it’s one of the more distinctive creatures you’ll find in a BC home.
What They Look Like
House centipedes are 25–50mm long (about 1–2 inches) with a flattened, yellowish-brown body marked by three darker stripes running lengthwise. Their most striking feature is their legs — 15 pairs of long, delicate legs that get progressively longer toward the rear of the body, giving them a feathery, almost alien appearance. The rear legs on a mature centipede can be nearly as long as its body.
They move fast. Alarmingly fast. A house centipede can cover more than 40 centimetres per second, making them one of the quickest arthropods you’ll encounter indoors. This speed, combined with their appearance, is why they trigger such a strong reaction — even in people who aren’t normally bothered by bugs.
Where You’ll Find Them
House centipedes are almost exclusively found in damp, dark, undisturbed areas:
- Basements — by far the most common location, especially unfinished basements with concrete floors and exposed foundation walls
- Bathrooms — particularly around drains, behind toilets, and under vanities
- Laundry rooms — the combination of warmth and moisture is ideal
- Crawl spaces — where ground moisture and darkness create perfect centipede habitat
- Utility rooms — around water heaters, sump pumps, and plumbing access points
They’re nocturnal hunters, so daytime sightings usually mean the population is large enough that competition is pushing some individuals into less-than-ideal hunting territory — or that the one you spotted was disturbed from its hiding place.
Why Centipedes Are in Your Basement
House centipedes don’t wander into your basement by accident. They’re there because your basement provides exactly what they need: moisture and prey. Understanding both factors is key to eliminating them.
The Moisture Connection
Centipedes lack the waxy outer coating that most insects have to prevent water loss. They dehydrate quickly in dry environments, which means they’re physiologically tied to damp conditions. If your basement humidity regularly exceeds 60%, it’s centipede-friendly territory.
This is particularly relevant for homeowners in Maple Ridge, Pitt Meadows, Coquitlam, and throughout the Fraser Valley. Our climate — with its wet winters, high annual rainfall, and relatively mild temperatures — means that basements in this region are consistently more humid than in drier parts of Canada. Homes built on slopes (common in Coquitlam’s Burke Mountain area and in the hillier parts of Maple Ridge) can have groundwater seepage issues that keep basement walls and floors damp year-round.
They Follow Their Prey
Here’s the part most people miss: house centipedes are predators. They’re not in your basement eating your stuff — they’re in your basement eating other bugs. Their diet includes:
- Silverfish
- Carpet beetle larvae
- Cockroach nymphs
- Spiders
- Earwigs
- Ants
- Bed bug nymphs
- Drain flies
A centipede in your basement is a strong indicator that there’s a food source — meaning other pest populations — sustaining it. In a sense, centipedes are a symptom. The real problem is the ecosystem of insects living in your basement that you may not even be aware of.
How They Get In
Centipedes enter through the same gaps and cracks that allow moisture and other pests into your basement:
- Cracks in the foundation (especially common in older Maple Ridge homes built before modern waterproofing standards)
- Gaps around plumbing and utility penetrations
- Floor drains without proper traps
- Gaps between the foundation and the sill plate
- Window wells and basement window frames
- Spaces around the clothes dryer vent
Are House Centipedes Dangerous?
Let’s address the question that’s probably driving your search: should you be worried?
The Short Answer: Not Really
House centipedes can bite, but they rarely do. Their jaws (technically called forcipules — modified front legs) can technically puncture human skin, but they’re not aggressive toward people. Bites typically only occur if a centipede is directly handled or trapped against skin — not from casual encounters. A bite, if it happens, produces a minor, localized reaction similar to a bee sting that resolves within a few hours.
They’re not venomous in any meaningful sense to humans. They don’t carry diseases. They don’t damage your home, your food, or your belongings. From a purely practical standpoint, house centipedes are beneficial — they actively reduce populations of genuinely problematic pests.
So Why Get Rid of Them?
Two reasons:
- They indicate a larger problem. A thriving centipede population means a thriving population of prey insects. You’re not seeing the silverfish, carpet beetles, and other pests that the centipedes are feeding on — but they’re there. Eliminating centipedes without addressing their food source means other pest problems will become visible once the predators are removed.
- Quality of life. Let’s be honest — nobody wants to encounter fast-moving, many-legged creatures in their home, regardless of how harmless they are. If centipedes are affecting your comfort in your own basement, that’s reason enough to take action.
Eliminating Centipedes and Their Prey: A Complete Approach
Killing individual centipedes is pointless if you don’t address why they’re there. An effective approach tackles moisture, prey populations, and entry points simultaneously.
Step 1: Control Moisture
This is the single most important thing you can do — and it benefits far more than just centipede control.
- Run a dehumidifier: Keep basement humidity below 50% during the warmer months. In the Fraser Valley climate, this typically means running a dehumidifier from April through October. Empty the reservoir regularly or connect it to a drain.
- Fix water intrusion: Repair foundation cracks, improve exterior drainage (downspouts should discharge at least 2 metres from the foundation), and address any groundwater seepage. In areas of Port Coquitlam and Pitt Meadows where the water table is high, this may require professional waterproofing.
- Improve ventilation: Ensure basement windows can be opened for cross-ventilation on dry days. If your basement lacks windows, consider a mechanical ventilation system.
- Check plumbing: Leaking pipes, dripping faucets, and condensation on cold water pipes all contribute to basement humidity. Insulate cold water pipes to reduce condensation.
Step 2: Eliminate Prey Populations
Reduce the food that’s sustaining centipedes:
- Reduce clutter: Cardboard boxes, old newspapers, stacked fabric, and stored items create harbourage for silverfish, earwigs, carpet beetles, and other prey insects. Replace cardboard with sealed plastic bins. Remove items you’re not using.
- Clean thoroughly: Vacuum along baseboards, behind appliances, and in corners where debris accumulates. Organic matter buildup in cracks and crevices feeds many of the insects that centipedes hunt.
- Address other pest populations: If you’re seeing silverfish, earwigs, or spiders in addition to centipedes, those populations need treatment. Centipede control that ignores prey populations is putting a bandage on the symptom.
Step 3: Seal Entry Points
- Caulk foundation cracks: Use hydraulic cement for active water cracks and polyurethane caulk for dry cracks.
- Seal around penetrations: Fill gaps around pipes, wires, and ducts where they pass through foundation walls or the basement ceiling. Expanding foam or caulk works for most gaps.
- Install proper drain traps: Basement floor drains should have a water trap (P-trap) that stays filled. A dry trap is an open highway for centipedes, drain flies, and sewer gases.
- Weatherstrip basement windows and doors: Gaps around basement window frames are common entry points, especially in older homes.
Step 4: Monitor
Sticky traps placed along baseboards, behind the water heater, and near floor drains serve as both a monitoring tool and a passive control method. Check them weekly — the types and quantities of insects you’re catching tell you what’s happening in your basement ecosystem. If you’re catching silverfish and earwigs but no centipedes, the centipedes are still finding enough prey to sustain themselves.
When to Call a Professional
DIY moisture control and exclusion work handles most centipede situations. But there are scenarios where professional intervention is the smarter move:
- You’re seeing centipedes frequently — multiple times per week. This suggests a large population sustained by a significant prey base. A professional assessment identifies what’s living in your basement beyond the centipedes.
- They’re appearing on upper floors. Centipedes on the main floor or in bedrooms indicate a large basement population that’s expanding its territory. This is beyond the “occasional visitor” stage.
- Moisture issues are severe. If your basement has chronic water intrusion, addressing the centipede symptom without solving the water problem is a losing battle. Sometimes the right first call is a waterproofing contractor combined with a pest control assessment.
- You want an integrated approach. A professional can treat both centipedes and their prey populations in a single program, using targeted applications in harbourage areas that maximize impact while minimizing product use.
At Canadian Pest Control, our basement pest assessments evaluate the entire ecosystem — moisture levels, entry points, prey populations, and centipede activity — to develop a targeted plan. Because eliminating centipedes without addressing the conditions that support them just means they come back next season.
Living Centipede-Free in Your BC Basement
Centipedes in your basement aren’t dangerous, but they are a signal. They’re telling you that your basement has the moisture levels and insect populations that sustain a predator. Address those underlying conditions, and the centipedes lose their reason to be there.
Start with moisture control. Seal the entry points. Reduce the prey. Monitor your progress. And if the problem persists or you want a professional assessment of what’s really going on down there, help is a phone call away.
Tired of finding centipedes in your basement? Call Canadian Pest Control at (778) 598-7378 or visit cpestcontrol.ca to schedule a free basement pest inspection. We serve homeowners across Maple Ridge, Coquitlam, Port Coquitlam, Pitt Meadows, and the Lower Mainland.