Exactly as the title says, exactly how big of a hole can a bat fit through?
I presume we are not talking cricket or baseball here.
According to my extensive research…
Some can get through a half-inch hole.
There are nearly 1000 bat species worldwide, with wingspans from about two inches up to six feet. What type of bat are you asking about?
According to this Purdue “wildlife conflicts” site
The spring after we moved into our house we found we had a nursery colony of bats in the attic. This was really a glorified crawlspace atop our 2-story home and had openings in the ends covered with steel vents that matched the siding on the house. The openings were less than half an inch wide, and we sat on the deck below and watched the bats squeeze themselves through. I’d swear they had collapsible skulls ;).
Come October the bats moved out for the winter and we added metal window screening to the vents. They now raise their batlings in the rafters of our machine shed, so everybody’s happy.
yes it is good and important to provide alternate housing for bats. if you don’t have nearby buildings like barns, sheds and the like then you could make some bat houses.