Silverfish and Centipedes in Hudson Valley Homes: Why They're There and How to Stop Them

The Moisture Pests of the Hudson Valley

There are two creatures that consistently unnerve Hudson Valley homeowners — not because they're dangerous, but because they're fast, surprising, and seemingly impossible to keep out. Silverfish and house centipedes are the defining moisture pests of older homes throughout Westchester County, Rockland County, and the Bronx.

If you've ever flipped on the bathroom light and watched a many-legged creature sprint across the tile at impossible speed, you've met the house centipede. If you've found small, silvery, carrot-shaped insects in your closet eating through a cardboard box of old photos, you've met the silverfish. Both are telling you the same thing: your home has a moisture problem they're exploiting.

Understanding Silverfish

Silverfish (*Lepisma saccharina*) are among the oldest insects on Earth — they've been around for over 400 million years, predating dinosaurs. They're about 1/2 to 3/4 inch long, silvery-gray, teardrop-shaped, and move with a distinctive fish-like wiggling motion.

What they eat: Starches and carbohydrates — paper, book bindings, wallpaper paste, cardboard, photographs, clothing (particularly cotton and linen), and pantry items like flour and oats. In older Westchester homes where boxes of documents and books are stored in damp basements, silverfish can cause real damage to irreplaceable items.

Where they live: Dark, humid spaces with minimal disturbance. Basements, crawl spaces, bathroom wall voids, attic eaves, and the spaces behind built-in cabinets. They're nocturnal and avoid light, which is why you rarely see them during the day.

Why Hudson Valley homes are vulnerable: The combination of stone and brick foundations in pre-war homes, high water tables throughout the county, and seasonal humidity creates basement environments with relative humidity above 75% — exactly what silverfish need to thrive. Homes in Hastings-on-Hudson, Dobbs Ferry, and Nyack are particularly susceptible due to proximity to the Hudson River and its associated moisture.

Understanding House Centipedes

The house centipede (*Scutigera coleoptrata*) is one of the most startling-looking creatures you'll encounter indoors — up to 1.5 inches long, with 15 pairs of long, delicate legs that allow it to move at remarkable speed across floors, walls, and even ceilings.

The good news: House centipedes are actually beneficial predators. They eat silverfish, cockroaches, bed bug nymphs, spiders, and other household pests. Finding centipedes means they have a food source — which means you likely have other pest issues they're feeding on.

The bad news: Nobody wants to share a bathroom with them at 2 AM. Their appearance triggers a visceral reaction in most people, and their speed makes them difficult to catch.

Where they live: Damp basements, bathrooms, laundry rooms, and crawl spaces. Like silverfish, they require high humidity to survive. They're nocturnal predators that hide in wall voids and under items during the day.

What Both Pests Are Telling You

When our team inspects homes in Yonkers, Spring Valley, and the Fordham neighborhood of the Bronx for silverfish or centipede complaints, we're really investigating a moisture issue. These pests are indicator species — their presence tells us something about the conditions inside your home.

Common moisture sources we identify:

• Unfinished basements without dehumidification — relative humidity above 60% sustains silverfish and centipede populations

• Foundation seepage — water infiltration through stone, block, or poured concrete foundations

• Bathroom ventilation failures — exhaust fans that don't actually vent outside, allowing moisture to accumulate in wall cavities

• Crawl space moisture — exposed earth floors without vapor barriers

• Dryer venting issues — dryer exhaust venting into the basement or crawl space

Effective Control Strategies

Step 1: Reduce moisture. This is non-negotiable. Without addressing humidity, any pest treatment is temporary.

- Run a dehumidifier in the basement year-round, targeting relative humidity below 50%

- Repair foundation seepage and grade soil away from the foundation

- Ensure bathroom exhaust fans vent to the exterior

- Install vapor barriers in crawl spaces

- Fix leaking pipes immediately

Step 2: Eliminate food sources (for silverfish). Store paper goods, photos, and documents in sealed plastic containers rather than cardboard boxes. Move cardboard storage out of damp basements.

Step 3: Seal entry points. Caulk gaps around pipes, seal cracks in foundation walls, and install door sweeps. Both silverfish and centipedes enter through remarkably small gaps.

Step 4: Professional treatment. When populations are established, targeted treatment with residual insecticides and desiccant dusts (like diatomaceous earth or silica aerogel) in wall voids, behind baseboards, and in crawl spaces provides lasting control. These products work by damaging the insects' outer coating, causing dehydration — particularly effective against moisture-dependent species.

When to Call BluesWay

If you're finding silverfish damage to stored items, seeing centipedes regularly in living spaces, or discovering either pest in large numbers, it's time for a professional pest inspection. The insects themselves are manageable — but the underlying moisture conditions they indicate can lead to far bigger problems, including mold growth and wood decay that attracts carpenter ants and termites.

BluesWay Pest Control provides comprehensive moisture pest treatment for homes across Pelham, New City, Haverstraw, and throughout the Bronx. We address both the pests and the conditions creating the problem.

Call us at (914) 968-8404 to schedule an inspection. We'll tell you what we find, recommend practical solutions, and treat the existing infestation — so your basement goes back to being a storage space, not a nature preserve.