I've had a major ant problem here at my house for the past few years. Using every kind of poison they sell at Wal-Mart, Home Depot, etc.
Coincidentally, I discovered a water leak in the wall that had been there since it was constructed back in the 80's. Long story short, some stupid muther******** ran a sheetrock screw through my water line in the wall and it slowly rusted out and had a super slow leak. The ants were always crawling on the driveway and exterior walls and would eventually come inside to visit.
Now that the horrible task of repairing the leak is done the ants have disappeared.
So make sure you don't have a small leak in a wall or around the house somewhere, cuz here in San Antonio, these little ants are ruthless and immune to most any poison other than lighter fluid and a match!!!
MSI X58A-GD65, firstname.lastname@example.org, EVGA 660 GTX SC SLI, Neutron 240 GB,2.75 TB Spindle Storage,ASUS DVD-RW, 6GB Patriot, Win 7 & 8.1 & Kubuntu Triple Boot, ASUS VK278 on DisplayPort.