I counted just under 300 little brown bats in 1 hour at dusk.
They crawl out of the vents and tiny holes between the wood slats on the walls.
That is my highest count in an hour, best before that was in the 60s.
That's fantastic. In a green space that ran behind our housing community you could stand, get bitten by mosquitoes, and watch about fifty bat's fly and eat. Stand still and you'd hear some of their echo location as they dived a few feet near your head.
Then one year there were no bat's. 😞
In my new neighborhood there's just a few but I was glad to find them.
It could have been as simple as someone redid their roof and closed up a hole the bats were in or a tree got cut down that housed them.
If you want to help and you are in a position to put a bat-house up on your home or plant native plant species that attract bugs for the bats to eat. Some bat species like moths and beetles. It really depends on where you are in the world to what you can do to help, look for a local bat society or wetland group and ask what you can do.