After vacuuming (and be sure to put the vacuum bag outside as soon as you're done), sprinkle Borax in your carpet and under all your seat cushions. You don't need a lot, especially if you're vacuuming daily, but it will kill fleas it contacts and help keep the population down. I did this with my cats and none of them had a problem with it. If you're worried about dog, or human sensitivity you could sprinkle the carpet and close of the room for a few hours. Just vacuum when you need the room (great for bedrooms that are empty all day, or the LR over night).