Here in PA, they are everywhere! 2 weeks ago, I heard a crackling in my wall. I went outside to see if it was something outside and I smelled smoke. So of course I freaked. I called DH ( who is a firefighter) and he came right home (made it in 5 minutes) with a couple of friends. They dismissed the fire idea because the walls weren't hot, but concluded it was vermin of the ant type when they climbed into the attic.
That was one of the worst noises that I have ever heard, the munching sound. I had no sleep for 3 nights, I dreamt of the roof falling down and I could HEAR them chewing on my house. Finally, the exterminator came (Orkin was great) and the noise stopped.
Now the plus side to all of this is that not only are the ants gone, but it's been 2 weeks and I haven't seen ANY bugs....no spiders, no millipedes, nothing.
They come back in a month for a second treatment and in the meantime, we are removing the railroad tie wall that are around the house as a future preventative measure.
But I also like that talc idea!