Tinton Falls homeowners know the pain of seeing dozens – sometimes hundreds – of millipedes congregating on basement walls after heavy rainfall or in humid periods. These creepy crawlers have 47 body segments and do not bite or cause structural damage, but the sheer volume of them can be distressing.

You often notice them overnight, congregating next to foundation walls or slowly creeping across concrete floors, leaving residents scratching their heads about when and how they came into the picture.

The explanation starts underground. The soil in Tinton Falls is rich in clay, which retains moisture  well. Millipedes typically travel in large groups when the ground is oversaturated to prevent drowning in wet soil. Your basement may not be where they want to call home – just where they go to escape. This realization that moisture is the driver behind this behavior helps to prevent recurring invasions.

Although sweeping them up may fix the immediate issue, long-term control generally requires speaking to pest control experts from Alliance Pest Services.

When the Ground Stays Wet, They Move

Millipedes thrive in damp soil, where they feed on decaying organic matter such as fallen leaves and wood. They require constant moisture because they breathe through their exoskeletons. If the ground is overly sodden, either from a long period of rain, excess watering, or poor drainage, its air pockets are lost, making it harder for them to breathe.

That is when large-scale movement begins. Migration events are often initiated in the field when soil moisture stays above 70% saturation for more than 48 hours

Exterior Moisture Traps That Trigger Basement Entry

Some typical landscape areas surrounding Tinton Falls residences create conditions that support the buildup of millipede populations adjacent to foundations, making basement entry nearly certain. These include:

  • Mulch beds against the foundation: Though those appealing thick mulch layers (especially wood chips) retain moisture and make that home sweet home for millipedes. If these beds are directly against foundation walls, millipedes will gather at that spot and find the crack or gap in the foundation.
  • Clogged or poorly positioned gutters. Each time downspouts empty out just a few feet away from the foundation or the gutters overflow during storms, water puddles next to the basement walls. And that leads to both the moisture issue that moves millipedes and the conditions  they require to enter.

Having dense ground cover in foundation plantings can also hold moisture against basement walls. Millipedes love humid environments, which we create in some of our gardens with plants like English ivy or pachysandra.

Why They Show Up Along Baseboards First?

Typically, when millipedes invade basements, they enter initially near the perimeter, particularly near wall-to-floor junctions. That pattern is not accidental. Pests prefer dark, sheltered areas with higher humidity, and the  basement baseboards provide just that. Walls are also vulnerable because they meet the floor: a ledge that can retain moisture more than other areas with airflow exposure (namely, open floor areas), and where exterior walls bring the cool, damp condition of the soil into the interior.

Most access points are located near floor level, which is where you will most often find small foundation cracks and gaps around utility entry points, specifically, where pipes, cables, or conduits enter or exit the foundation. Despite being larger, millipedes can compress their bodies to fit through gaps as small as three millimetres.

Breaking the Moisture-to-Migration Cycle

To address the ongoing millipede problems, both the reasons for their migration and the means of their entry need to be resolved. Surface treatments that eliminate visible millipedes do not prevent new millipedes from entering once the next rain saturates the soil around the house. Appropriate control measures aim to minimize moisture contact and create barriers.

Experts at pest management companies such as Alliance Pest Services address millipede problems by conducting an extensive exterior inspection to identify moisture sources and potential entry points into the structure. They investigate grading patterns, drainage systems, and foundation perimeter conditions that generate pest pressure.