I have tried various things for various critters. We
haven't really had a problem with ants as much tho. We had a
problem with fleas last year - there are about 20 wild cats that
cross our yard :(
I have used borax soap (not boric acid) sprinkled with table
salt in the carpets. I let it sit for a few hours when we
went out and the cat was outside. I then vacuumed and it did
help get rid of the little buggers. Salt dehydrates adults
and from what I have read, the borax hits the larvae stage.
Now I use garlic in my yard, it smells like an Italian
restaurant for an hour or so but it works well to prevent many bugs
and annoyances. If it would keep the wild cats out I would be
even happier.