Ants are looking for water. We get ants at our sticks and bricks a couple of times a year and there is always a water source nearby.
Get a bottle of Terroant, and put several squares of aluminum foil near the ant infestation. Pour the Terroant out onto the foil and the ants will find it and will take the Terroant back to the nest.
Getting the bait back to the colony is the only way to impact the problem. Do not remove the Terroant until all of the ants are gone, they will pack off the bodies of their dead comrades.
If you watch the ants, you will see a trail that will go back to the colony, they leave a marker when they find a source of water or food, and they all use the same route.
Terroant is nontoxix to humans or pets.