I found some Terro at our local A-Boy Hardwear. It's borax mixed with sweetner, with seems less toxic than some other choices. You're supposed to tear these cheesy orange cardboard squares off the box and put a drop of Terro on them.
Some of the orange squares are being ignored. Others are overrun with ants who are busy drinking the Kool-Aid, so to speak. There are many, many, many more ants than I had thought. Many, many more.