If you have standard house (carpenter) ants, there are a few things you can do ...

First, resign yourself to the fact that these beasts live in your house. The nests (yes plural) are in the walls, under the foundation, and probably in the yard outside.

Second, eliminate sources of WATER in areas where you see ants gathering and create sources of water in areas where you would rather they be (waaay out in the yard!). Do this by wiping down sinks and tubs with a dry cloth and leaving drain plugs closed during the summer months when possible.

Third, cinnamon powder, lavender, diatomaceous earth, and Borax are all ant deterrents (all but lavender will actually KILL them). When I had ants in my aviary, I used a small tray of Borax and Powdered sugar (50/50) to encourage the ants to drag the borax into the nest and dry out the new larvae (this causes the queen to move her operation).

Fourth, find where ants are coming in and fill the hole with caulk. This won't stop them completely, but it will force them to find another entry point.

Failing all of those, hire a pest control service. A good one can minimize ants in a month or two.