Millipedes will typically make their way into houses in the fall or spring. They may be between half an inch to 1.5 inches long and either brown or gray in color. They will curl up if bothered. They don’t bite but can be a nuisance. Once inside the house they will likely seek out the basement or bottom levels since they are seeking moisture. They usually perish indoors by dehydration; however, they can live longer in basements that are moist. They generally thrive in environments that are humid and moist and where there is a lot of organic matter. A flower bed with lots of mulch, for example, is a great home for them.
A good way to keep millipedes from entering the house is to get rid of any mulch or vegetation that’s dead and next to the house. It’s also important to caulk cracks in the house, repair windows, etc. This will essentially “seal” the insects out of the house. This is a long-term solution.
For a quick fix, chemical applications may be used outside. Choose a product that is for use around the perimeter of the house. The product should be sprayed in a 10- to 15-foot strip around the home. You will also want to spray the outside of the basement wall, door sills, and window frames. Animals and people should not walk on insecticides when the products are wet. However, the area that has been sprayed may be walked on once the product has dried.
To get rid of millipedes inside your house, you can sweep and discard them or step on them and then vacuum. Indoor insecticides may be used to control millipedes in a house as well.