Pest Management Fact Sheet #5029
James F. Dill, Pest Management Specialist
Clay A. Kirby, Insect Diagnostician
Description & Biology
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 drier ground. In the fall, they also search for 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.
Sanitation is the most important factor in keeping populations of millipedes down. This means, you deprive the creatures of their habitat. As when dealing with slugs, earwigs, sowbugs etc, 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. You should also locate gaps in doors and other household entry points, then incorporate barriers such as door sweeps.
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. Materials that can be used in this way and also as band treatments of synthetic pyrethroids such as permethrin, bifenthrin, deltamethrin, and cyfluthrin or Sevin (carbaryl). If millipedes are getting in through cracks and crevices in the foundation, these can also be treated.
Once millipedes are in the house, typically the garage and/or the cellar, they usually do not live very long. For this reason, we suggest that you just sweep them up and dispose, instead of using a pesticide.
When Using Pesticides
ALWAYS FOLLOW LABEL DIRECTIONS!
Pest Management Unit
Cooperative Extension Diagnostic and Research Laboratory
17 Godfrey Drive, Orono, ME 04473
1.800.287.0279 (in Maine)
Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.
© 2016, 2018 | Reviewed: 2020
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