Two little eyes peer up at a tiny wooden box, eagerly searching for signs of bats. My 3-year-old daughter does this several times a week even though I’ve told her it’d be months before a bat likely finds the bat house and decides to nest.
It might seem odd to want to attract bats to your yard, but those little winged mammals are pretty special creatures. They’re nighttime pollinators responsible for helping more than 300 species of plants and trees grow, including bananas, mangoes, and agave. According to The Nature Conservancy, bats’ value to U.S. agriculture is estimated at $23 billion annually. But for many homeowners, the joy of having bats has to do with the fact that they eat a variety of pests, including Japanese beetles, cucumber beetles, and other invasive insects that can wreak havoc on a garden, not to mention mosquitos. Bat Conservation International reports that one little brown bat can eat 60 medium-sized moths and more than 1,000 mosquito-sized insects in one night.
“We enjoy outdoor activities such as tending our garden and relaxing, however, the mosquitoes also enjoy our yard,” Kippi O’Hern says. She designed a pagoda-inspired bat house to coordinate with the other structures in her Florida yard. “We wanted to find a natural way to control our mosquito problem. A neighbor recommended we build and install a bat house.”
Interest in bats has been increasing over the past few years. Individuals like O’Hern have added bat houses to their properties. Governments—including the state of Massachusetts—have encouraged residents to install them. Even businesses have started selling everything from the completed bat houses and the tools to construct them to the plans to build them.
Most successful bat houses are made out of non-pressure treated wood such as cedar, plywood, or a combination of both. They should be at least 24 inches tall and 14 inches wide and include vents for airflow and a rough interior for bats to grasp onto.
“As more attention is being brought to climate change, people are trying to find ways to contribute and make their own impact. Bat houses are one of those ways people can make an impact—it’s actionable, and they can see the results in less bugs and less pests,” says Harrison Broadhurst, the cofounder of BatBnB which not only sells bat houses, but also works to educate consumers about the wonder of bats. “Since the pandemic, we’ve also seen people paying a lot more attention to their own backyards and trying to make it a better space.”
If you’re thinking, But why do bats need houses, don’t they live in caves?, you’re not entirely wrong. Some bats do live in caves, and while they tend to hibernate in the winter, bats look for other places to nest while they raise their young in the warmer months. As more forests have been cleared, bats are experiencing their own housing challenges. Evidently, it’s a hard time to be a bat!
The Nature Conversancy estimates that there are more than 1,100 species of bats, and more than 40 species of bats are located in the United States. Most bat species, including the types that eat moths and other insects, are microbats. The little brown bat is the most common in the U.S., but other species are based on the region they live in and the type of food they eat the most. More than half of the bat species found throughout the U.S. are either in decline or listed as endangered, and habitat loss is one of the biggest threats bats face.
Yet attracting bats to bat houses isn't always easy. In Whitefish Bay, Wisconsin, Megan Sutton and her family wanted a bat house to help control mosquitoes, but they realized they needed to make some design tweaks to entice bats. “My husband and son made it together, and my son refused to put a vital piece of wood on the inside for the bats to hang, so our bat house had no residents,” she says. “However, he’s agreed to remodeling to better accommodate guests this summer.”
Out in Florida, Kippi O’Hern’s pagoda-inspired bat house hasn’t attracted any bats, but she’s not giving up on it either. “We did more research and learned that you need two or three bat houses to attract bats. So we are planning to build more bat houses,” she explains. “I know we will enjoy having bats to help us keep our insect problem in check.”
According to the USDA Forest Service, it often takes up to two years to attract bats to a bat house and even then, only about 15 percent of bat houses end up occupied. Still, a more recent study by Bat Conservation International found that 52 percent of the bat houses in the survey were occupied.
- If you’re going to build your own bat house, a good place to start is by looking at plans created by Bat Conservation International or the National Wildlife Federation. BatBnB provides a hanging guide as well as other resources on its website.
- Think about where to place the bat house. Harrison Broadhurst notes that sunlight is the biggest factor. The bat house should get at least six hours of sunlight per day and be located away from other objects, such as trees or ledges. Bats might think predators can hide in these places and therefore will stay away from the bat house.
- Although bat houses can be placed on trees, poles, or houses, BatBnB has found the most success with bat houses placed on buildings, again away from other objects.
- The bat house should be placed at heights between 15 and 20 feet.
- You want to locate the bat house in a low traffic area as you might notice some guano (bat poop) on the ground that shouldn’t be touched without gloves on.
- Finally, be patient. It can take a couple of years for bats to find the house, but once they do, they’ll come back year after year.