I had a bat house for years my dad built. Never got any bats, laf. We took it down a year or so ago after i found out a friend of mine got bats in her roof. Cost her a great deal in clean up. So I got a little spooked trying to house them on my little plot of property. Laf.
Wood ducks are a nicer group...
I had serious (protected!) Brown Bat bat issues at my other farm - 3rd floor walk-up attic, insulated, and then for some reason my ex put plastic up across the insulation and it made a perfect haven for bats, which could get in, in some of the TINY gaps in the eves. One time I had 6 live bats in the house! *SHUDDER* I got very brave, and I never killed a one - just caught them in a towel and tossed them back outside.
When it came time to sell, I spent $12K having the entire attic torn apart, cleaned and sanitized and new insulation blown in on the floor. And did those bats ever return to THANK ME? Nope, LOL!
But, it’s the new owners problem now! Yay!