Effectively removing them from a residence is a pretty involved (and expensive) process if you don't want to use poison and if you don't want them moving back in.
To begin with, if you have any kind of colony at all, not every bat leaves every night. What is done, is the house is draped all over with large nets with mesh too fine for bats to get through. When the bats leave at night to forage, they end up having to crawl down the sides of the house to get out from under the nets. When they get back later, not being smart enough to go down under the net and crawl up the side of the house to get back in, they go find somewhere else to roost. After about a week, you can be sure you've got all the bats out of the house. At that point, you have to go around and calk up/seal up every opening they can get in through, which is to say anything larger than about a dime. That done, you're bat free. As you can imagie, it's not a cheap thing to have done or to do yourself, given the cost of those nets. I guess nets are available that you just put up and leave up, but I would guess that, even if you put them up really well, over time weather and sunlight would cause them to deteriorate. Might be worth a try, though:
https://www.industrialnetting.com/b...G_Ia5YuduzT3Yka3JjOCK0huoJxoCuPUQAvD_BwEI've never seen instances where bat houses were very effective at getting them to leave a spot they'd already colonized.
I have a friend, recently retired from the NYSDEC as a fish and wildlife technician. In addition to crawling into dens and putting tracking collars on hibernating bears, one of his winter jobs was going into big caves and counting hibernating bats...thousands and thousands of bats....don't think I'd care for it.
