As an update of How to get rid of ants, let me share a technique that seems to be working.
I’ve been trying the Ortho Home Defense Max spray, active ingredient of Bifenthrin. You spray the holes or crevices where you see ants coming out of or going into. A little while later, no ants use those holes any more. Eventually, the ants find a new way to get in and you repeat the process of spraying the deterrent into the crevice.
It is supposed to last for 12 months, and it has actually kept the garage area free of ants for a few days now. The ants did manage to find a new entrance in the last day, but after spraying that too, the trail stopped. Maybe the spray doesn’t actually kill, but as long as it keeps them out of the house, that’s good enough for me.