Are you talking about those horrible itty bitty ants?! We tried everything (sprays, flour, etc.) to get rid of them and nothing kept them away. Finally hired an exterminator.
He told us that these particular ants -- sit down for this one! -- live in the walls of your house!! Super Ugh!!
He said that sprays only tell them "we can't go there again" so they move to another spot/wall and invade a new area. The best thing to use is a deterrent that they bring back to their nests where it kills them and the nest.
Worked great for almost a year but, now that we're having ocassionally warm weather, I'm starting to see them in a room that was packed with stuff when the exterminator did his thing. We signed up again for this year -- believe me, there will be NO packed rooms to hinder his job!!