When I was back in Texas earlier this year, my Mom's house had these little harmless ants in the shower every day.
They call them crazy ants down there..
Since my Mom is elderly, I dont want to use any sprays if possible.
She had a pest control contract, so I got those people over and we looked all over and found an actual "trail" of ants coming and going out of the heater/a/c Closet.
They were coming in from the little hose that carries the moisture out of the A/C unit to an outside wall and it drips out there..
So, we put some clear Bait from a Syringe on top of that pathway tube.
They started coming from Everywhere inside that heater closet to get that bait and go back down that hose, to the outside, and to their nest somewhere underground. ( I never found it but think it was next door in their yard)..
They removed a huge amount of the clear Bait within 24 hours. The bait blog was the size of say, an Orange Slice Candy, etc..
Within 48 hours, there were just a few ants wandering around the heater closet and by the 3rd day, they were all gone..
This stuff must have killed all or most of them and hopefully the queen mother

...
That's how we do it in Texas...

Dan F