glad to hear things are better... fleas can live in a sort of 'hibernation' state for a long time. when carbon dioxide becomes more prevalent in the atmosphere, meaning there are some mammals around, they sort of wake-up & go to town - & it can get really bad, really fast, especially if the previous tenants moved without treating an infestation. the good news is, once you get them out, it'll probably never be as bad. but yes, i've seen some bad ones around here, too - even in dorm rooms on campus where pets are not allowed. the fleas prefer the cats, but they'll eat off of you, too. carpets are bad because it gives them a place to wait in dormancy. that's one reason i have hard floors throughout my house.