A bat house is a specialized wooden shelter designed to provide a safe, warm roosting space for bats during the day. Installing one is a practical step toward wildlife conservation, offering a replacement for natural roosts lost to development. These structures are highly beneficial for pest control, as a single bat can consume thousands of insects, including mosquitoes, each night. Successfully attracting a bat colony, especially a maternity colony, hinges on placing the house in an optimal location.
Selecting the Ideal Mounting Height
The height at which a bat house is mounted is a primary factor in determining whether bats will use it. Experts recommend installing the bottom of the bat house a minimum of 12 feet off the ground, with 15 to 20 feet being the ideal range for success. This elevated placement serves two important biological functions.
The first is protection from ground-based predators, such as raccoons and domestic cats, which are less likely to access a high roost. The second relates to the bats’ unique flight mechanics. Bats require a vertical drop of several feet to gain the necessary momentum to take flight, unlike birds.
Mounting the house at a sufficient height ensures a clear, unobstructed drop zone, allowing bats to exit the roost safely and efficiently. In regions with high ambient temperatures, a slightly higher placement may expose the house to cooling breezes. In cooler climates, the goal is to maximize solar heat gain, which is achieved effectively within the 15-to-20-foot range.
Maximizing Bat House Success Through Location
A bat house’s occupancy rate depends more on its location than its design. The most frequent cause of an unoccupied bat house is inadequate solar exposure, which affects the required internal temperature. Maternity colonies, the primary target for installation, require a consistent internal temperature between 80°F and 100°F for the development of their young.
To achieve this warmth, the house should face south or southeast, receiving a minimum of six to ten hours of direct sunlight daily. This orientation allows the house to absorb and retain heat throughout the day, maintaining the high temperatures needed during cooler nighttime hours. Placing the house near a large structure that radiates heat, such as a building wall, can further assist in thermal regulation.
The surrounding habitat must provide a clear, open flight path for the bats approaching and departing the roost. Ensure there are no trees, wires, or potential perches for aerial predators within a 20-to-30-foot radius of the entrance. The ideal location is also within a quarter mile of a permanent water source, such as a pond, stream, or lake, as bats need to drink shortly after emerging for nightly foraging.
Recommended Mounting Surfaces and Installation
Choosing the correct mounting surface is as important as height and sun exposure, as the material influences temperature stability and predator access. The best options are the side of a building—preferably a wooden, brick, or stone structure—or a dedicated wooden or metal pole. Mounting on a building provides excellent thermal mass, allowing the structure to absorb solar heat and passively warm the bat house, leading to stable internal temperatures.
Metal or wooden poles are effective because they maximize sun exposure and minimize predator access in open areas. When using a pole, it should be sturdy and secured in the ground with concrete to prevent movement. Attaching two bat houses back-to-back on a single pole, with one facing south and one facing north, provides bats with a choice of two different thermal environments.
Mounting a bat house directly onto a living tree is discouraged and often leads to failure. Trees create excessive shade, preventing solar gain, and their branches obstruct the clear flight path bats require. The rough bark of a tree trunk also offers an easy pathway for predators to climb and access the roost. The house should be securely fastened using durable, weather-resistant hardware, such as lag screws or U-bolts, to ensure it remains stable against high winds.