Moved from Polydesmida.

Moved from Millipedes.

Well, with millipedes, they're pretty much harmless. They feed on rotting wood, soil material and other organic stuff. Your best bet is to get rid of the food. You might want to call a professional so they can inspect the basement and see what they are eating. They also like damp, dark areas. If killing them doesn't work, maybe some sort of natural repellent might at least make it less desirable of a home.

They are naturally resistant to most insect killing sprays, so most 'commercial' stuff won't do the trick.

They say making sure there's very little to no thick vegetation around the foundation is important too. And to make sure that there is good drainage so the soil isn't soggy. Stuff like old cardboard, newspapers, wood and whatnot in the basement are sources of food and shelter.

I've heard that if you use a dust like Sevin around the perimeter of your home (a 4-5 inch wide band around the foundation) that it does a good kill.

A nuisance I'm sure, but they're not really much danger. I like millipedes, but I understand you don't want piles of them!

My wife saved a bunch of potting soil over the winter in the garage (does not freeze) she is now battling them in every outside potted annual. They eat the base of the flowers killing them. She is trying systemic granuals (made by Bayer) so far they are still winning.