A spoonful of mixed corn syrup, water and borax will kill them all and their sugar sucking queen, too.
Unfortunately, my dog likes that stuff too... boiling/scalding water works really well, as does steam... more work though.
When I lived in California, I had persistent ant problems. I tried everything and the little bastards kept coming back. Sprays, borax, etc. One day, after I had doused my baseboards with the most “extreme” ant killer they had at my local hardware store, which left them crawling through oily residue since they refused to die, I took out a spray bottle of 409 to clean it all up. It killed every one of them, cleaned up the oil, dead ants and borax residue, and they didn’t come back. 409 is now my first choice for bug killer, but I question whether or not it’s a good idea for kitchen surfaces, because it is obviously toxic!