I work in a homeless shelter in Iowa and we have a terrible problem with them. The exterminator told us they were pretty much eliminated in the United States about fifty years ago. Then they banned the insecticide that was used to kill them and they have been on the rise ever since. We have tried everything to get rid of them, but with so many people coming and going, they are taking them with them when they leave and bringing them in when they come. We have not found any way to completely get rid of them. They are small, but not too small to be seen - bigger than a flea, smaller than a fly.