It is very important for nursery colonies to raise their young under warm conditions. You should even paint your bat house black to absorb more heat. Use a non-toxic, latex paint for your house and only paint the outside. Remember that where you mount your bat house plays a major role in the internal temperature. Houses can be mounted on such structures as poles, sides of buildings and tall trees without obstructions.
Houses placed on poles and structures tend to become occupied quicker than houses placed on trees.
Houses should face south to southeast to take advantage of the morning sun. Your bat house should be mounted at least 15 feet above the ground, the higher the house the greater the chance of attracting bats. They will be abundant through out the summer and into late fall. If bats do not roost in your house by the end of the second summer, move the house to another location. In southeastern states you can attract certain bats species if the house is placed in total sun, other species prefer partial sun, and some bats use bat houses placed in total shade.