Judith Latham wrote:

I like the idea of getting two flea collars for your ankles. I might do
this for work as we have fleas in the building. We know we have because
one of the younger members of staff, Katie, caught one and brought it to
me on her finger to ask what it was. She dropped it on my desk and I
immediately killed it. It was a flea it looked like a flea, jumped like a
flea and crushed like a flea, it was a flea. We have suspected it for a
while as we've been getting a few bites. Now we have proof. We've reported
it but that was three weeks ago and nothing has been done. Katie still has
it on the piece of paper in a plastic wallet. she even emailed a copy to
the appropriate person although it just looked like a dot.

If you have fleas in the building, you probably have mice and/or rats,
as well! (I had rats in my attic, which led to "oriental rat mites" in
my clothes closets.) That was REALLY a trip - they breed much faster
than fleas, so the spray didn't really help. I ended up using flea
spray twice a day, and spraying my clothes before I put them on in the
morning.