If the windowsill in question is NOT one that your ferrets, children, or
any other household animal are likely to sit in, then I have a suggestion.
I learned this from my grandmother, and it *really* works!  Sprinkle Comet
Cleanser (you know, the scrubby powder cleaner stuff that turns blue when
it gets wet?) on the windowsill.  The ants will *not* cross that line!
They stay on their side, you stay on your side, everyone's happy.  I have
done this for years and I never have an ant, except for the ones that my
children bring in as "pets."
 
Now if I could just find such a solution for fruit flies...<sigh!>
 
Chana & Co.
6 Kids, 3 FurKids, 1 mangy excuse of a ferret-hating cat, 1 neurotic
rabbit, and a parakeet named Chompers.
<<have you hugged a ferret today?>>
[Posted in FML issue 3461]