Attracting bats to a backyard offers tangible benefits, primarily through natural pest control and the promotion of local biodiversity. These nocturnal insectivores are highly efficient predators, with a single bat capable of consuming thousands of insects, including mosquitoes and moths, in a single night. Welcoming bats provides an environmentally sound method for managing garden pests, reducing the reliance on chemical insecticides. Creating a hospitable habitat requires specific modifications, focusing on providing safe roosting structures and a reliable food supply.
Building the Ideal Bat Home
The primary physical attraction for bats is a dedicated roosting structure, commonly known as a bat house. The design of this shelter is crucial, as bats seek secure, warm crevices for raising their young and resting during the day. A successful bat house design includes multiple chambers with roosting crevices that are approximately three-quarters of an inch wide.
Taller houses, ideally twenty inches or more in height, are preferred because they create a temperature gradient, allowing bats to move to find their preferred warmth. The interior surfaces must be roughened or grooved to allow bats a secure grip for clinging. The house should be constructed from untreated wood, with all exterior seams caulked tightly to prevent drafts and water intrusion. Proper ventilation is necessary to prevent lethal overheating, especially in warmer climates.
Installation location is the most important factor in attracting a colony. The house must be mounted on a pole or a building at a height between twelve and twenty feet off the ground. Mounting the box on a tree is discouraged, as it offers less sun exposure and makes bats vulnerable to predators. The ideal placement receives a minimum of six to eight hours of direct sunlight, preferably facing south or southeast, to ensure high internal temperatures for maternity colonies. The structure should be positioned in an open area, at least twenty feet away from obstructions like tree branches or utility wires that could impede their flight path.
The color of the exterior is important for temperature regulation, with darker colors absorbing more heat and being preferred in cooler regions. In areas with intense sunlight, a lighter color or positioning the structure to receive some afternoon shade can prevent overheating. Back-to-back mounting on a pole can also help by providing a wider range of temperatures for the bats to choose from throughout the day.
Cultivating a Rich Food Source
A successful bat habitat requires a steady, abundant supply of insects, which are the main diet for most North American bat species. This supply is sustained by creating a biodiverse yard that supports various insect life. Begin by planting native, night-blooming flora that attract nocturnal insects, particularly moths.
Plants featuring pale, scented flowers, such as evening primrose or moonflower, are particularly effective because they are easily seen and smelled by night-flying insects. A variety of native plants, including trees, shrubs, and ground cover, supports a diverse insect community throughout the season. This landscaping variety ensures a consistent food source from early spring until late autumn when bats prepare for hibernation.
Introducing a water feature to the backyard, such as a pond or a large birdbath, also helps cultivate a food source. These features attract insects like mosquitoes and midges, which lay eggs in the water and emerge as easy prey for foraging bats. A water source also provides a place for bats to drink while they are actively hunting. Maintaining a compost heap or a log pile in a shady area encourages beetles and other insects, further increasing the food available in the immediate vicinity of the roost.
Minimizing Hazards and Promoting Safety
Eliminating common backyard elements that pose a direct threat is necessary for maintaining a safe environment. The immediate removal of broad-spectrum pesticides and insecticides is necessary, as these chemicals reduce the insect food supply and can poison bats. Relying on the bats for pest control allows the insect population to thrive, which sustains the colony.
Reducing light pollution is another important step, since bats prefer a dark environment for emerging and foraging. High-intensity, upward-facing white lights are especially disruptive, as they can delay emergence or cause bats to abandon a roosting site altogether. If outdoor lighting is necessary near the roosting area, using low-intensity, downward-focused amber or red lights is less harmful to navigation and feeding patterns.
Protecting bats from domestic pets is important, particularly during the initial installation of a bat house. Cats and dogs may pose a threat to any bats that fall from the roost or are flying close to the ground. Positioning the bat house on a tall, smooth pole, rather than a structure that pets can easily access, helps to mitigate this risk.