Something fast just ran across your basement floor. Or you found what looks like it has way too many legs. Or there's something with pincers on its tail that turned up in the bathroom at midnight. These are three distinct insects that show up regularly in Westchester homes — silverfish, earwigs, and house centipedes — and they're misidentified often enough that homeowners end up treating the wrong problem.
Here's the more useful framing: all three pests share a common root cause. High humidity. Westchester's older housing stock — stone foundations, unfinished basements, crawl spaces that haven't been updated in decades — creates the moisture conditions these insects need. Get the moisture right and you address all three at once. Spray without fixing the humidity and you'll be back in the same spot next season.
But first, you need to know which one you're dealing with.
Not sure what you're seeing? Call (877) 938-6799 to connect with a licensed pest control provider in Westchester County.
What Did You See? Quick ID Tool
Click the description that best matches what you found. You'll get an ID, what it means, and what to do.
That's a silverfish.
What it means: Silverfish need high humidity to survive — above about 70% RH. Their presence in your basement or bathroom tells you moisture levels in that space are elevated. They eat starch and cellulose: book bindings, paper, cardboard, wallpaper paste, and stored fabric. The damage is real but typically slow.
What to do: Humidity reduction first. Run a dehumidifier, fix any active leaks or seepage, and improve ventilation. Remove cardboard boxes and paper storage from damp areas. Pesticide treatment helps but won't produce lasting results without fixing the moisture. If populations are high, a licensed provider can treat cracks and voids more thoroughly than store products reach.
That's an earwig.
What it means: Earwigs live outdoors in moist soil and decaying organic material — mulch, leaf litter, garden debris near the foundation. They enter homes seeking moisture, especially during dry spells outdoors or during rain events that saturate their outdoor habitat. They're not looking to establish indoors permanently; they're opportunistic entrants through foundation gaps and door sweeps.
What to do: The pincers look threatening but earwigs are harmless — they rarely pinch and the pinch is weak. Reduce exterior moisture conditions near the foundation (pull mulch back from the foundation wall, clear leaf debris), seal gaps in door sweeps and foundation, and treat the perimeter if they're entering in numbers. Interior populations are usually small and self-limiting once entry is blocked.
That's a house centipede.
What it means: House centipedes are predators. They're in your home because other insects are in your home — silverfish, small flies, cockroach nymphs, spiders. They also need humidity to survive. Finding one occasionally isn't alarming. Finding them regularly in numbers means there's a food supply sustaining the population, which points back to a broader moisture and pest situation.
What to do: Don't just treat the centipede — address what it's eating. Reduce basement humidity, assess for silverfish or other moisture-pest populations, and consider a professional inspection if you're seeing them frequently. Centipedes are almost impossible to eliminate directly; controlling their prey and their moisture environment is far more effective. They're not dangerous and won't damage your home, but their persistent presence is a useful diagnostic signal.
Silverfish: The Starch Eater
Silverfish (Lepisma saccharina) have been around longer than almost any other insect order — their basic body plan predates wings in insects. They're primitive, soft-bodied, and completely dependent on moisture. The carrot-shaped silhouette, the rapid fish-like movement, the silvery scales. Once you've seen one you recognize it. But a lot of homeowners mistake them for something worse on first encounter.
Their damage is real but gradual. Irregular holes in book pages, thin patches in stored fabric, yellowing of paper that's stored in damp conditions. They're eating the starch and cellulose in those materials. A cardboard box of books in a damp Westchester basement is an ideal food source and habitat simultaneously.
The reason store-bought sprays produce only temporary results: you kill the visible insects but the humidity that sustains the population remains unchanged. New silverfish — from eggs already in the space, or from adjacent areas — move back in and the cycle repeats. A dehumidifier running in the basement is more effective against silverfish over a season than any pesticide alone. See our eco-friendly pest control page for moisture-management approaches that reduce chemical reliance.
Earwigs: Outdoor Pests That Come Inside When Wet (or Dry)
European earwigs (Forficula auricularia) are fundamentally outdoor insects. They live in damp soil, leaf litter, and garden mulch. The pincers at the tail end — technically called cerci — look alarming but serve as defensive appendages and are used in mating competition. They can pinch if you handle one directly, but the pinch is minor and earwigs aren't venomous.
They enter Westchester homes for two opposite reasons: when it's too dry outside (they're seeking moisture), and when it's too wet outside after heavy rain (they're flooding out of saturated soil). Either way, they're not trying to establish a permanent indoor population. They're entrants of opportunity through foundation gaps, deteriorated door sweeps, and low-to-ground entry points.
You're most likely to find them on the basement floor or near ground-level entry points. Rarely upstairs. The control approach for earwigs emphasizes the exterior: pull mulch back from the foundation (a 6-inch mulch-free zone helps), eliminate leaf debris near the house, and seal the gaps they're using to get in. Interior populations typically self-limit once entry is blocked.
House Centipedes: The One You Don't Need to Panic About
Nothing in a Westchester basement generates a more visceral reaction than a house centipede running across the floor at speed. They're fast — up to 1.3 feet per second. They have 15 pairs of legs in adults. They move like nothing else in a residential setting. And yet they're arguably the most benign of the three pests on this page.
Scutigera coleoptrata, the house centipede, is a predator. It actively hunts silverfish, small cockroach nymphs, spiders, and other soft-bodied insects. It's providing a service, though an unsettling one. It can technically bite if handled but the bite is comparable to a mild bee sting and is very rarely reported. It doesn't transmit disease. It doesn't damage structures.
The reason persistent house centipede populations matter is diagnostic rather than direct. A basement with year-round centipede activity has a food supply sustaining that population. Something is there for them to eat. Finding and addressing what that is — usually silverfish, sometimes small fly populations from organic debris, occasionally cockroach nymphs migrating from an adjacent space — is more useful than trying to treat the centipedes themselves.
The Common Thread: Moisture First, Treatment Second
All three of these insects require elevated humidity to survive in a structure. Below roughly 50% relative humidity, silverfish can't reproduce effectively, earwigs lose their motivation to stay inside, and centipedes lose their prey base. A basement dehumidifier running through Westchester's humid summer months is the single most effective intervention for reducing moisture-pest populations.
From there: fix active water intrusion at the foundation, improve subfloor ventilation if you have a crawl space, and eliminate the organic debris and cardboard storage that silverfish use as both food and shelter. Pesticide treatment on top of those corrections works well. Pesticide without the corrections gives you temporary suppression and a recurring problem.
If you've addressed moisture and you're still dealing with significant populations, a professional assessment can identify what you might have missed — whether that's a hidden moisture source, a pest species you haven't identified, or an entry route that needs exclusion work. See our pest problem signs guide and the related winter pest activity guide for how moisture pests behave year-round in Westchester homes.
Frequently Asked Questions
Why do silverfish keep coming back even after I spray?
Because spraying kills individual insects but doesn't change the humidity conditions that sustain the population. Silverfish need high humidity to survive and reproduce. If the basement or bathroom stays humid, silverfish will continue to thrive regardless of pesticide applications. Lasting control requires humidity reduction — a dehumidifier, fixing moisture sources, improving ventilation. Pesticide is a useful secondary tool, not the primary one.
Do earwigs actually pinch people?
Technically yes — an earwig's cerci can pinch if it's trapped against skin or handled. In practice the pinch is weak and causes no real injury. Earwigs aren't venomous and don't transmit disease. The alarming appearance of the pincers far exceeds the actual threat. If you're seeing earwigs inside, the relevant question is why they're there — almost always moisture and outdoor debris near the foundation.
Are house centipedes a sign of a serious pest problem?
Not a serious problem in itself — house centipedes aren't dangerous and don't damage structures. But they're a reliable indicator of elevated humidity and the presence of other small insects they're feeding on. A persistent centipede population suggests there's a food supply sustaining them, which points to a broader moisture and pest situation worth addressing.
How do I tell the difference between silverfish and earwigs?
Silverfish are flat, tapered (carrot-shaped), silvery or gray, and move in a rapid fish-like side-to-side motion with three long tail filaments — no pincers. Earwigs are darker brown, more uniform in body width, and have the distinctive curved pincers at the tail. Both are found in humid areas, but silverfish are more likely near paper and fabric storage while earwigs typically enter near soil-level points.
What's the fastest way to reduce all three of these pests?
Address the humidity. All three require elevated moisture to survive and reproduce indoors. Run a dehumidifier in the basement, fix active water intrusion, improve ventilation, and eliminate organic debris near foundation entry points. Once humidity drops below about 50%, the conditions sustaining these populations are removed. Pesticide treatment works well as a concurrent measure but won't produce lasting results without the moisture fix.