These insects have started to congregate outside my basement stairs (at night, I can find them in the hundreds) and have started to enter my house. I am now finding 10-20 crawling around the basement every day and I want to know what they are so I can ultimately determine how best to get rid of them. I have attached pictures of them as well as their entrance point. If anyone can help, it would be greatly appreciated.
Flat-backed millipedes, basically nuisance pests that no real damage (except perhaps to very tender seedlings such as in greenhouses). Moisture management is the best control - they need abundant moisture/high humidity in order to thrive.