Hundreds of Worm-Like Bugs Crawling Inside? Here’s How to Stop the Invasion

Seeing millipedes curled up on your basement floor? Finding dozens crawling up foundation walls? Waking up to find them scattered across your bathroom or garage? When millipedes invade, they don’t come alone—they come in waves.

Here’s what you need to know: Millipedes aren’t infesting your home like roaches or ants. They live outside and migrate inside in massive numbers when conditions trigger it—usually heavy rain, drought, or temperature extremes. Killing the ones you see doesn’t stop more from coming. You need exterior treatment and entry point exclusion.

We’ve been handling millipede invasions in NYC since 2010. We treat exterior breeding grounds, create barriers, and seal entry points to stop the migrations.

Millipedes invading by the dozens? Call +1 (347) 210-4646 or request service online. We’ll stop the invasion and keep them outside where they belong.

Understanding NYC Millipedes

Common Millipedes (Various Species)
What they look like: Dark brown to black, cylindrical, worm-like bodies with two pairs of legs per body segment. Range from ½ inch to 1½ inches long. Move slowly in wave-like motion. Curl into tight spirals when disturbed or dead.

Where they live: Outside in mulch, leaf litter, under stones, in decomposing vegetation, beneath logs and debris, in damp soil. They feed on decaying organic matter—they’re decomposers, not pests in the traditional sense.

Why they invade: Environmental triggers force mass migrations indoors:

• Heavy rain saturates soil, flooding their habitat
• Drought dries out normal living areas
• Temperature extremes (hot spells or cold snaps)
• Seasonal breeding migrations in spring and fall
• Loss of habitat from landscaping or construction

The problem: They don’t bite, sting, or damage property, but hundreds of millipedes crawling across your floors and walls is disturbing. They can emit defensive fluid with unpleasant odor when handled. Dead millipedes stain surfaces if crushed.

Why Millipedes Choose Your Building

Exterior harborage right against foundation – Thick mulch beds, dense ground covers, leaf piles, stacked wood, vegetation touching walls—these create perfect millipede breeding grounds inches from your home. When conditions change, they simply walk inside.

Moisture accumulation near building – Poor drainage, downspouts emptying near foundation, low spots collecting water, overwatered gardens—millipedes thrive in damp conditions. Buildings creating moisture problems attract massive populations.

Easy entry through foundation – Foundation cracks, gaps under doors, utility penetrations, basement window wells, crawlspace vents, expansion joints—older NYC buildings have countless openings. Millipedes can squeeze through surprisingly small gaps.

Seasonal weather patterns – Fall brings temperature drops and rain, triggering migrations. Spring brings heavy rain and breeding activity. During these peaks, millipede pressure on buildings becomes intense.

Landscape against building code – Dense plantings installed against foundations trap moisture and organic debris. This creates ideal millipede habitat directly adjacent to your home’s perimeter.

Protected overwintering sites – Millipedes seek warm, protected areas for winter. Heated basements and crawlspaces are attractive when exterior temperatures drop.

Our Millipede Control Strategy

Step 1: Exterior Inspection & Source Identification
We inspect around your building perimeter:

• Identify millipede harborage areas (mulch, vegetation, debris)
• Assess moisture conditions attracting populations
• Locate entry points and access routes
• Evaluate landscape contributing to problem
• Determine migration triggers and timing

Treatment starts outside because that’s where millipedes live.

Step 2: Exterior Perimeter Treatment
The primary control method:

• Barrier treatment around entire building foundation
• Treatment of mulch beds, vegetation, and harborage areas
• Application in cracks, gaps, and potential entry points
• Treatment of foundation walls up to window level
• Focus on areas with heaviest millipede activity

Exterior barriers stop millipedes before they reach your building. This is where professional-grade products make the difference.

Step 3: Harborage Modification Recommendations
We identify landscape changes that reduce millipede populations:

• Mulch reduction or replacement near foundation
• Vegetation trimming and thinning
• Debris removal (leaves, wood, stones)
• Drainage improvements
• Creating vegetation-free zones around perimeter

You don’t have to eliminate all landscaping, but modifications significantly reduce pressure.

Step 4: Entry Point Exclusion Guidance
We document every gap, crack, and opening:

• Foundation cracks needing repair
• Door sweeps requiring installation or replacement
• Utility penetrations needing sealing
• Window well screening needs
• Crawlspace vent protection
• Basement window gaps

We seal accessible gaps during service. Major repairs are your responsibility, but we provide detailed guidance.

Step 5: Interior Treatment (When Necessary)
For active invasions:

• Crack-and-crevice treatment along baseboards
• Entry point applications in basements and garages
• Treatment in crawlspaces if accessible
• Spot applications in affected areas

Interior treatment provides immediate relief but doesn’t stop exterior populations.

Step 6: Follow-Up & Seasonal Maintenance
Initial treatment shows results within 1-2 weeks. Seasonal follow-up treatments during peak migration periods (spring and fall) prevent future invasions. Properties with chronic millipede pressure benefit from quarterly exterior treatments.

Timeline for Millipede Control

Week 1-2: Immediate reduction in new millipedes entering building. Existing interior millipedes die off or leave.

Week 3-4: Near-zero interior activity under normal conditions.

Ongoing: Seasonal retreatment may be necessary during peak migration periods (typically April-May and September-October).

Weather events: Heavy rain can temporarily overwhelm barriers, requiring additional treatment.

Millipedes respond well to exterior barrier treatment, but environmental conditions can trigger new migrations requiring maintenance service.

Warning Signs of Millipede Invasions

Visual evidence:

• Dozens to hundreds crawling on foundation walls
• Finding them in basements, garages, or first-floor rooms
• Seeing them curled up dead on floors
• Concentrated activity near entry points and damp areas

Seasonal patterns:

• Invasions during or after heavy rain
• Activity spikes in spring (April-May)
• Fall migrations (September-October)
• Worse during humid, wet weather

Environmental indicators:

• Thick mulch beds against your foundation
• Standing water or poor drainage near building
• Dense vegetation touching exterior walls
• Accumulated leaves and organic debris

If you’re seeing millipedes regularly or in large numbers, you have exterior populations that will continue invading without treatment.

Why Professional Treatment Beats DIY

We treat where millipedes live – Spraying inside doesn’t help because millipedes don’t live inside. Professional exterior barrier treatment stops them at the source—in the landscape and at the foundation.

Our products last longer – Consumer sprays wash away with first rain. Professional formulations provide residual protection lasting weeks, even through weather.

We use proper coverage – Effective millipede control requires treating the entire building perimeter, up foundation walls, and into landscaping. This requires equipment and product volume homeowners don’t have.

We identify entry points – Most people don’t notice the dozens of gaps millipedes use. We find and document every one, providing a roadmap for exclusion work.

We address root causes – Landscape contributing to problem, moisture issues, harborage areas—we identify what’s creating millipede populations and how to reduce them.

Seasonal timing matters – Treating before migration periods prevents invasions. We know when millipede pressure peaks and schedule accordingly.

Preventing Millipede Migrations

Modify exterior landscape:

• Reduce mulch to 2-3 inches maximum, or eliminate within 12 inches of foundation
• Replace mulch near building with gravel or stone
• Trim vegetation away from exterior walls
• Remove leaf litter, logs, and debris near foundation
• Create a dry zone around building perimeter

Improve drainage:

• Direct downspouts away from foundation (minimum 5 feet)
• Fix low spots where water collects near building
• Improve soil grading around perimeter
• Don’t overwater gardens and plantings near foundation

Seal entry points:

• Install or replace door sweeps on exterior doors
• Seal foundation cracks with appropriate filler
• Fill gaps around utility penetrations
• Screen basement windows and crawlspace vents
• Weatherstrip doors and windows at ground level

Reduce exterior lighting:

• Millipedes are attracted to lights at night
• Use yellow bulbs less attractive to insects
• Install motion-activated lights instead of constant lighting
• Keep exterior lights away from doors when possible

Maintain barriers:

• Schedule exterior treatment before peak migration seasons
• Reapply after heavy extended rain
• Monitor for activity and treat early signs immediately

Stop the Millipede Invasion

Look, finding millipedes scattered across your basement floor isn’t just unpleasant—it’s a sign that exterior populations are massive and your building has entry points they’re exploiting. This won’t fix itself, and interior sprays won’t stop exterior populations.

We’ll treat your property’s perimeter, create a barrier millipedes can’t cross, and show you exactly what needs sealing to keep them out permanently.

Call us at +1 (347) 210-4646 or request service online. We’ll stop the invasion and prevent future migrations.

New York Exterminating, Inc.
1115 E 13th St, Brooklyn, NY 11230
Licensed & Certified Since 2010

Millipede control starts with exterior barriers and exclusion.