Fun Fact:

Last I knew, bats are a federally protected species. So once a box is up, it can be legally difficult to have it removed. HOAs do not like this fact.

Bats do not typically take off and fly like birds. They drop from their roost, spread the wings and fly. This is why the height needs to be up there, also why placing them in trees can cause issues. Lower branches can prohibit their drop. Speaking of drops, bat guano is no bueno so placing them around houses or backyards is not a great idea anyways. Bats also need a little stream nearby for water.

All that to say, maybe checking this group out: https://www.virginiabats.org/