Oh UGH! I've never had ants in here EVER. But there I was crawling around on the kitchen floor poking under things (looking for a cat toy, what else?) when all of a sudden there were all these ants marching out from somewhere. They just ..APPEARED! I couldn't tell if they were coming from under the baseboard or under the washing machine (which was running).
I kept squishing them but more kept coming. I couldn't imagine was had attracted them. I'm not the best housekeeper in the world as far as dust balls and clutter, but I don't have food or crumbs around in the kitchen, I wipe the floor every night after the cats eat.
So I got the thin rod that I use to swipe under the washer for toys (was just about to do it before the ants, in fact) and what comes out but an old capsule of egg yolk lecithin. Part of the capsule was dissolved (or eaten) and about half the contents were gone. Could it have been that, that attracted them? It couldn't have been there very long, as I am always looking for toys under there. I don't remember dropping it.
Shuddering away I wiped up as many as I could but they kept coming. I went downstairs and got the jug of diatomaceous earth (organic, food grade) that I always keep handy, and started dusting (by hand) all along the edges of the baseboard where they were either coming from or going under. When the washer drained and spun out, I pulled it out but there was nothing else under there, not even any dust (I sweep the stick thing under there regularly looking for toys)
Since dusting I haven't seen any more ants. Hope that does the trick. So glad I keep the DE handy. URRGGGGHHH.