Fleas are pretty hard to get rid of without a good fogging/fumigating. Vacuuming the house isn't going to help, either. You are never going to get them all. If you're fogging one room at a time, you might as well be spraying water. You have to nail the whole house, and you have to do it repeatedly. Most of them are going to be in carpet, but the little buggers can survive anywhere. Nuke 'em once a week for a month or so, and you'll get rid of them. It took a whole summer for us to fry all of them in our old house because it never occured to us to nuke the yard, too. If you have animals that go outside (we had 3 dogs), you need to spray out there, too.