Yes, ferrets mark their territory.  I can't say, of course, if that is
what yours is doing, but my gibs are always dribbling urine or scent
marking (or whatever it is they do) to show all the other boys what
they're going to encounter if they should have the nerve to come out at
the same time.  It is the same spots, and they always head there first
thing when they are let out of their cage.
[Posted in FML issue 4141]