I moved to a lake house last fall. Had like 6 bats living in a small attic space. I know they can become a MASSIVE problem. Took about a week to find out where they were coming in and out. LITERALLY a small spot under a shingle that you could barely fit the handle of a butter knife. So I put a nest cam on the roof to confirm. First I tried a bat tube. Those things suck unless it is in an ideal location for its intened application where the end of the tube hangs 3ft in mid air. I swear those bats would spend an hour walking around finding the end of the tube to go back in. FINALLY I had to wait till they all flew out at 9:30PM (ON THE DOT). At about 10PM I'd crawll on the roof (stunk like bat urine - UGH) and caulk in the spot. Had to do this a few times.

Then I paid $1400 to have a black plated mesh thats bent in a Z screwed all around my ridge vent. Made by a company in northern Michigan. Have to be a contractor or builder to buy. I had a contractor friend purchase and drop ship to my house. Then paid a roofer $800 to install. STEEP PITCH 2 story. I wasnt getting up there. Ridge vents are like an effing welcome sign.

GOOD LUCK. The bat exterminating theives in my area wanted $5000 and didnty do clean up and DEFINEATELY didn't go to the lengths I did.

Now the neighbors have bats POURING out of a big gap in the soffits of thier house. At least they aren't in mine. That told me "they're YOU'RE bats"