There does seem to be lots of pretty good info on bat nesting, and quite a few people interested in setting up for them; although it's somethimes hard to tell who knows what they're talking about and who's just hallucinating a good story. Your own experience will be the best guide, if you can get things started with a colony.

Of course, after living in your attic for a while, your particular bunch of bats may have acquired unusual personality quirks that wouldn't necessarily be representative of general bat social conventions. ...

Did you ever have the notion that they were watching you?

John