I had the small black sugar ants in my kitchen in
LARGE numbers
about 10 years ago. I tried ant powder and other chemicals to no avail. Then I cut off their food supply. They were chasing sugar so I put a plastic tray on the benchtop half full of water. Into that went a smaller plastic tub and into that went anything they might want to eat. Eventually, everything they were interested i was in the tray surrounded by a water barrier. Beyond that, I let them go about their business. It took several weeks but eventually the ants went away. They've never come back. I imagine they paid down some sort of chemical signature to say, "don't bother, no food here."
Joe