Boric Acid +1. Just buy some Borax from the grocery store (laundry aisle). Among other attributes it repels all kinds of crawling pests without spreading poison around. It also does wonders for laundry so you can finally wash that pink towel. If you are really curious buy some of those glue pads used to catch mice (they are not expensive) and place them around your baseboards in your kitchen and bathroom. Within a few days you will be able to see what is really going on when you are gone or asleep.