Very first research I did after we got online about 12 years ago was
how to deal with an indoor carpenter ant problem. Found a university
(Michigan?) professor's web site with a recipe of equal parts canned
dog food (the greasier, the better) and cheap jelly, with a touch of
boric acid. Idea being, as others have said, to kill the queen. This
was actually an exterminator's advice; he said we were wasting our
money on monthly service and suggested we invest some time in getting
to the nest.
So, it was really interesting -- lengthy, but interesting -- to watch
the larger and larger ants do the 'gathering' as the smaller ones
obviously began to die off. Eventually, the guys that were coming out
approached a good inch and a half or better in size. Creepy, and oh so
hard to gulp and look the other way so they could take the bomb back
to Her Majesty. Finally, after countless weeks, no more ants, and I've
never seen another one since.I know that, theoretically, carpenter
ants don't do sugar/grease like the little red guys, but all I can say
is it worked for ours.
Key is, again, patience. My husband was of the more-is-always-better
philosophy, no matter what the project, so we got nowhere fast when he
was busy overdoing the boric acid. I finally took over the cooking and
we made progress.