What I did for my mom. I observed the ants in her kitchen for days making her exasperated since I wouldn't let anyone kill them. I found their nest (outside under a rock) and how they were getting in (old milk delivery box) WHY they were coming in (for water) There was a leak under the sink (where I found a second colony of carpenter ants.)
I relocated the carpenter ants, fixed the leak and sealed the holes. No more unwanted breakfast guests!
futurebird