The attic has several levels and lately I hear it in an area that I cannot access unless I take a ladder up there with me (but there's no structure for the ladder to stand on). It's always under the fiberglass batting (or possibly in the wall at times) so it's difficult to find, and of course they are not interested in traps, bait, etc. Also, they hibernate in the winter, so it's not always active, and most of the time it would be when I'm asleep, which makes the sucker difficult to find.
I've heard of people using the sticky traps near the access point, but I'm not positive where that is yet. I have two ideas though. One is easily accessible, the other requires me to do some yoga.
Bats are a protected species in Michigan, but if it finds its way into my living room that suckers going down.