Millipedes: Understanding Their Behavior and Control

Meet the humble millipede, that worm-like creature munching on mulch and slowly making its way across the lawn, only to dry out against your home's foundation. What brings these little guys to such an end, and why do hundreds of their relatives join them in this seemingly pointless invasion of your peaceful home? Understanding millipede behavior can help us better manage their presence.

The name "millipede" means "thousand legs," but the record-holder, a California species, has just 750 legs. Our local millipedes have fewer than 350. With all those legs, you'd think they'd trip over themselves, but if you look closely, you'll see that they move their feet in waves along their undersides. Amazingly, they usually have no more than six legs on the ground at any time, with the rest in motion, prepping for the next step.

So, why all the legs? 

Millipedes live in moist, decaying plant litter and spend most of their lives underground, feeding and mating in wet, marshy areas. Their short antennae are protected by a blunt shell, and many species have either no eyes or very basic ones. They play a role similar to earthworms, breaking down plant material and aerating the soil. Their many legs act like a mini bulldozer, giving them the muscle and traction to move through the soil.

In western Washington, the most notable pest species thrive along our ocean dunes, where dune grasses and frequent rains create perfect conditions. Small puddles and marshy areas can support huge populations throughout the summer, but as these dry out in late July and August, millipedes move en masse to find better habitats. If your home is near one of these migrations, you might see thousands of them in just a few hours, which can complicate pest management efforts.

Millipedes are harmless but have defenses. Many can release smelly fluids, and those in our dunes contain cyanide compounds that repel many animals. These compounds react with vinyl and plastics, so stepping on one or letting it lie dead on the floor can leave a permanent mark, much like a tea stain.

The best defenses against these migrations are tight door and window seals and eliminating hiding spots near your home's foundation. If your home is overwhelmed by these creatures, regular millipede control through exterior treatments can help. Our basic maintenance services address this insect concern, so don’t be miserable—let us know. 

We can help!