How do I get rid of millipedes/centipedes that crawl into the house; and if stepped on smell very bad? Is there something that can be sprayed or spread outside to keep them out? Or does something need to be done inside?
Millipedes feed on decaying organic matter, and if they get into the house, won't live very long indoors. Centipedes, however, could live indoors if they find other insects or spiders to feed on. You may be able to prevent either from getting indoors by carefully caulking areas around doors and windows. If that doesn't do the trick, a perimeter spray of an insecticide around the foundation of the house should keep most of them out.