Bat house roosting bats live everywhere in the United States except Hawaii. Hawaiian hoary bats roost only in tree foliage. It should work nearly anywhere else if properly mounted. In arid areas where daytime temperatures drop by more than 20 degrees at night, bat houses are less likely to succeed unless mounted on buildings which act as stabilizing heat sinks. Additionally, in cold climates they should be painted dark colors and placed to receive as much direct sun as possible. See our painting guide for more information.