I lived in a house once that was prey to at least 4 different kinds of
ants, from the little "sugar ants" to carpenter ants.  The sugar ants
found my ferret cage, on the 2nd floor, within 8 hours of my moving in
there.  And there were lots.
 
Anyway, I solved the problem by completely cleaning up the ferret cage,
taking it to the other side of the ants' entry (in this case, a window),
and attaching it to the wall.  I had one of those 2 story black cages, it
is small, probably, than the ones available nowadays.  Anyway I attached
it to the wall about a foot up, maybe, I could still open the cage (the
door opened downwards) and the ferrets could still come out.  That way
I could access the bottom of the cage easier and clean out any wayward
food.  I also put the food on the bottom level to reduce food "spray".
Ants do not "smell", they just wander, this way absolutely no part of the
cage touched the carpet, which was brown and hid those little buggers
quite successfully.  They were more obvious on the white wall.  I never
saw them near the cage.
 
Minta
[Posted in FML issue 4517]