Any suggestions? We have one of those propane wall mounted fireplaces, hooked up but we rarely use it. The exhaust outlet is a three inch pipe that ends a good fifteen feet up the back wall.

As I sit here typing, something is banging around in there somewhere (I can't see it) every few minutes. It isn't talking (as in bat chittering or weasel squeaking), but other than mice, the only critters that have tried to move into our house have been weasels and bats. Of course, The Man is away and The Cat is too young to cope.

Perhaps I should sing to it, thus frightening it back up the pipe?