I've got an old stone & sand basement that has fleas really, really bad
from the previous owner (well, her cat). When I first moved in, a 10-second
trip to the basement would mean at least 40 fleas on me by the time I made
it back to the top of the basement stairs. I've tried bug bombs, followed
by the last 9 months with a professional pest service who comes all the
time (I call them every time I go down there because I always have at least
5-10 fleas jump on me). They have tried every chemical they have legal
access to use, but nothing has worked. No pets (or people) use the
basement, right now it is useless space. The pest control service has
expressed some concern about the total amount of pesticide they have
sprayed in the last year- the only reason they haven't stopped altogether
is because the area they are spraying isnt living space.

So now I'm stuck with these invincible fleas. Does anyone know of any
alternative methods I should try? So far I haven't gotten any good ideas,
and the funniest suggestion I've gotten was from a co-worker who suggested
throwing a few dozen cats in the basement as "flea sponges", then carting
the cats out. I'm an animal lover, so I wont take that suggestion seriously
;-) but I am looking for real options...

Thanks,
Keith