Bats can eat more than 1,000 insects per hour and will consume 50 to 100 percent of their weight each night eating various bugs such as gnats, crickets, moths, mosquitoes, locust and flies. Bats often live for more than 30 years, so installing a bat house can be a great long-term method of insect control.
Several Internet sites offer free instructions for building a bat house, or you can pick up a ready-made house from your local hardware store or garden center. Before choosing a house, decide how and where to mount it, as some locations may determine the size and style of the house.
Step 1: Install the bat house in late fall or early winter to assure the home is ready when bats return in the spring.
Step 2: If the bat house is being installed to provide housing for bats destined to be evicted from a home or chimney, install the bat house 2-6 weeks prior to removing the bats from their current residence.
Step 3: Mount the bat house 12 to 25 feet above the ground. Mounting the house under the eaves of a two-story home or atop a singular pole works well.
Step 4: Choose a sunny location to mount the house. Typically, a southern exposure is recommended. Bat houses need 6-8 hours of sunlight to stay warm. Consider painting the outside of the house a dark color to encourage heat absorption.
Step 5: Keep bat houses at least 20 inches from branches, structures and other areas where predators, such as hawks and owls, can perch. If the house is mounted in a tree, bats often have difficulty locating and entering the structure.
Step 6: If possible, locate the house within 1,500 feet of a lake, stream, pond or other water feature. Bats need water to survive.
Step 7: Do not install the house above doors or windows where bat droppings could be a problem.
Step 8: Do not install a bat house on metal siding or near bright lights, though having a light to attract insects is beneficial for attracting bats.
Step 9: Plant a wide variety of plants, trees and bushes in the yard. Bats are attracted to diverse habitats. Trees and flowers attract bugs, which are vital to the bat’s survival.
Bats will move into a bat house 50 to 60 percent of the time. If after two years bats have not moved into the house, move the house to a new location.