Millipedes usually go unnoticed in the summer because of their nocturnal habits and tendency to disperse. The common species are found in dark, damp, cool places. They feed almost entirely on decomposing organic matter, which would seem to make them beneficial. However, they can become a nuisance in and around homes.

Maine’s common millipedes (which are diplopods and not insects) are up to 3/16 inch thick and up to 1-1/4 inch long. The body of a millipede has many segments, with two pairs of legs on each segment.

Water-saturated soil forces millipedes to the surface and higher ground. In the fall, they also move about to seek better over-wintering sites. When one or both of these conditions exist (i.e., during wet fall weather), it is common for large numbers of millipedes to be found in garages, and to a lesser extent in basements.

Management

Sanitation is the most important factor in keeping populations of millipedes down. By this means, you deprive the creatures of their habitat. As when dealing with slugs, earwigs, sowbugs and the like, never give millipedes a place to hide. Any kind of debris or decomposing organic matter is likely to attract millipedes. Even mulch can become a good habitat.

If an unbearable amount of millipedes are getting into the house, application of a residual pesticide may be warranted. Outside, spot treatments around areas where millipedes are gaining entry may help. A material that can be used this way and also as band treatment is Sevin (carbaryl). If millipedes are getting in through cracks and crevices in the foundation, these can also be treated.