Ahhhh Ants

[antproblems]

I live near Davis Square, and I've recently realized that I've got a carpenter ant problem - the little jerks came out of nowhere, and now they're exploring all over my apartment. They are not focused on any one area (no trail to follow), and they are concentrated in a few rooms (with crummy windows), so I think the nest may be outside. Any recommendations to go back to an ant-free existence?
Edit to add: I do have a cat, and would prefer not to poison her.