Not likely, but they can be coming in on people's clothes or on mice
and rats.

--
T.E.D. (tdavis@gearbox.maem.umr.edu)

I doubt it, fleas live off blood and wouldn't survive being packed in
litter.  I don't know how it's getting in your house, but since your cat is
so young, possibly they were in a larvae stage when checked by the vet and
not seen?  The life cycle of a flea varies from 2 weeks to 8 months.  Or
possibly they were carried in by a human?

Keep up the Advantage and maybe give your cat a flea bath.

Not from the litter. Perhaps there were flea eggs hidden on the edge of the
rugs/walls and they hatched. They can stay dormant for a long time. Or, you
carried them in on your shoes, pants from the lawn? or you have mice, rats with
fleas? or you pet a friend's pet with fleas? Also, Advantage doesn't always
kill all the fleas nowadays. That's why I changed to Frontline. It's also
really impossible to state that a cat definitely has no fleas whatsoever. He
could have had an egg or flea larva in his fur that the vet did not see. Just
keep treating with Advantage or get Frontline.

Fleas would not be spread through fresh litter (but eggs *can* be sheltered
in used litter).  Flease are easily spread by other animals or can be
brought in on your shoes or other clothing if you have fleas in your yard or
if you (or your visitors) come in contact with other animals.  My vet once
described flea eggs as "timed release eggs" because they can hatch at
intervals over a long period of time.  This means that you may need to use
Advantage for several months.  In addition, broadcast insecticide in a wide
perimiter around the *outside* of your house if you do not have children or
other pets than could be harmed.  If that is a problem, spread a very small
amount up against the foundation of the house.  You should also treat the
inside of the house, then vacuum thoroughly and empty the bag or cannister.
It is a good idea to cut a flea collar into several small pieces and vacumm
them into the bag or cannister after it has been emptied.  That should catch
anything that might hatch from eggs that might be retained inside the vacuum
cleaner.  However, do *not* use a flea collar *on* your kitten.

MaryL