As a public service announcement, I highly recommend diatomaceous earth (DE) powder for genocidal war against the ants.
Here in CA (and I guess other states in the Southwest) we have, over the last few years been invaded by some tiny little South American ants. I first got them in my condo in Santa Barbara just before I moved here a few years ago. While I'm not Felix Unger, I keep a clean house. You cannot leave even a crumb of food out with these things. Not a drop of juice that might have splattered out of a glass as you poured. If you do, there will be thousands of these things within the day if they have a colony nearby, or worse, you will create a colony in your domicile.
I tried every chemical and natural spray there was, but could not get completely rid of them except in Winter-Spring, and then they'd pop back up in Summer. I moved before I got to the point of burning down the condo complex.
Starting last Summer, I got them here. Same deal - tried everything and the only thing that kept them completely away was Winter. When they came back in force this Summer, I broke down and called the exterminator. While he sprayed liquid outside the house, inside the kitchen and the wall outlets (where they were coming from), he dusted with a powder. He didn't tell me what it was, but the ants were gone. He said they could still come back occasionally, but dusting would take care of them again.
Anyway, long story much longer, I searched for what that dust could be and found the DE at Lowes, which looked like the likely candidate. The bottle says "78% DE, 22% other ingredients (whatever they may be). A month after the exterminator was here, ants (a much smaller quantity than before) started coming out of an outlet on the other side of the kitchen. I used the DE on them, and a couple of days later they were all gone. Even when I left food out.
I thought I'd share as I'd not heard of DE for ants before, and it's simply awesome. Plus no chemical smell. It can take a few days to work, because as the exterminator told me, they get it on them, bring it back to the nest, then as they interact they spread it, eventually to the queen.
Highly recommended.