If you'd prefer to install your bat house on a pole, you have some options to consider.
You want to make sure any pole you use is rated to hold 15-25 pounds.
4x6 treated lumber is a great option, or a round wooden pole. You can also use a steel pole, at least 2" diameter, a schedule-40 galvanized is ideal.
Local hardware stores or fencing companies are great places to look for a good pole.
Here is our guide for installing on a metal pole, and our guide for installing on a wooden pole.