Bat House Research

After years of collaborative research, the Organization for Bat Conservation has documented the key requirements for successful bat houses.Some of the main considerations to success include 3/4-inch roosting spaces, 4 to 6-inch landing area, and tall (at least 16 inches) and wide (at least 12 inches) roosting compartments. Research also shows that as the number of chambers increase, the occupancy rate rises. Houses placed on poles and structures tend to become occupied quicker than houses placed on trees. Bat houses should face south or east to take advantage of the morning sun. When painting the bat house, use non-toxic (water-based), latex paint to paint and only paint the outside. Your bat house should be mounted at least 15 feet above the ground.

Bats return from migration and awaken from hibernation as early as March in most of the U.S., but stay active year-round in the extreme southern U.S. Bats will be abundant through out the summer and into late fall. Most houses used by bats are occupied in the first 1 to 6  months (during the first summer the bat house was erected). If bats do not roost in your house by the end of the second summer, move the house to another location.

The following is information about successful bat houses reported to OBC:

Mounting location:
  • 64% on sides of buildings (houses, garages, or barns)
  • 30% on poles
  • 6% on trees (dead or mature)
Height above the ground:
  • 5% mounted 10 to 12 feet above the ground
  • 75% mounted 15 to 18 feet above the ground
  • 20% mounted 20 to 25 feet above the ground
Amount of sun:
  • 14% received 2 to 5 hours of direct sun
  • 34% received 6 to 8 hours of direct sun
  • 52% received 10 or more hours of direct sun
  • 50% painted brown or black
  • 50% left natural (most were cedar, which grays over time)
Multiple bat houses:
  • 25% of the bat houses occupied were mounted with other bat house in the immediate area
Number of Bats:
  • 10% had 1 bat
  • 33% had 2 to 6 bats
  • 35% had 12 to 24 bats
  • 22% had 50 or more bats
© 2012 Organization for Bat Conservation