We had a problem a couple of years ago and vet recommended Cheristin Flea treatment for cats since Advantage and Frontline didn't seem to be working, so far it's working. She also recommended we use 20 Mule Team Borax on rugs and furniture to prevent reinfection. She said it was not harmful to pets or people, sprinkle on and leave for a few hours and vacuum off. It dries out the shell of the flea so it dies and also destroys the shell of the eggs. It worked and was inexpensive.