All those ant traps and crap like that have never worked for us. But for some reason, if you just get some good ant killer, and spray it all around their point of entrance they're usually gone after about a week or two. You have to spray it again at least once a week because it seems to wear off, but this has worked for small ants as well as the larger carpenter ants.
It works best, if you start doing it right after they start showing up in your house. If you wait until it gets really bad, it takes longer for them to give up.