I agree. My daughter had a flea infestation last summer because she forgot (????) to use a flea preventative for a couple of months. They were so bad in her house that they were jumping on the humans. My mom and I went down for a day visit and I decided to leave Lady home. It just wasn't worth it. Even with a flea preventative they will still get bitten before the fleas die and itch like crazy.
We sprayed our legs and ankles with Off Deep Woods (w/DEET) before we even went in her house, and left our bags in the car. When I got home I basically striped down just inside the door and washed everything in hot water.
One female flea can result in an infestation in just a matter of weeks. Not worth it IMO.
Those poor pets. They are probably full of tapeworms, too, since they have fleas. Why don't people use a flea preventative? For a cat and Jack Russell, you can get a bottle of Frontline spray for $25 and will last several years.