Ants will move in the fall and spring and take the same route if not disturbed, I live in an old building with many types of ants, not fire ants, I know all their routes. I have a garden and the ants do their job, I have my weapons, and they know that the kitchen is off limit's, when I moved in the building there was grape ivy growing on one side, One Idiot would pour something out his window to kill it from his upstairs bathroom, a new tenant got it in his head to take down all the ivy and disturbed the ecosystem that had been on the roof and lived in the vine for many years that's when the ant's invaded and water start leaking into the building. Sometimes its easier to leave well enough alone.