Skip to main content

Build a Bat Box Home for your Flying Neighbors this Halloween

Posted by Lara T. Murray, Research and Development, USDA Forest Service in Forestry
Oct 28, 2020
Mexican free-tailed bats exiting Bracken Bat Cave
Lots of scary legends and incorrect information about bats have led many to be unnecessarily frightened of bats. (USDA Forest Service photo)

Bats are the only mammal with a natural ability to fly. Maneuvering with great elegance and awe-inspiring precision, they can hunt in complete darkness. They pollinate over 500 plant species, providing us dietary staples like bananas and avocados.

As one of the most diverse and ecologically important groups of mammals in the animal kingdom, bats should be the subject of great reverence. Yet they have long been feared and underappreciated due to a reputation for carrying disease and their association with all things spooky. Today, almost half of the bat species in the U.S. are in decline due to loss of habitat and disease, putting the ecosystems they are so integral in sustaining at risk.

USDA Forest Service scientists believe we can better coexist with and conserve these flying marvels by creating bat-friendly habitats in the areas we occupy. With warm, humid, sheltered spaces for roosting, bats are naturally attracted to buildings. Most of the time, they are uninvited guests, but perhaps we should reconsider that attitude.

Might there be ways to construct buildings with bat-friendly features that are safe for residents and bats? How can we better engage citizen scientists and conservationists to support threatened bat populations by creating safe roosting spaces?

Forest Products Laboratory biologist Martin Pfeiffer is answering those questions by equipping builders, educators, local government, and homeowners with the information they need to support bats in our built environment. In a recent report, he synthesized guidance and sources of information on building and positioning bat boxes, as well as better accommodating them within existing structures.

“It comes down to temperature and texture”, says Pfeiffer about building bat boxes within or outside buildings. Maternity colonies need to be kept at a constant warm temperature (between 80 and 100 degrees), so generally that means good southern exposure and vents to regulate the heat. Bat boxes should also be constructed of wood that has a rough texture to allow bats to roost and maneuver.

As urban areas expand, the role humans have in providing shelter for bats may become even more critical. In fact, for some bat species, human structures have become a lifeline, slowing population declines and perhaps even staving off extinction. Their historical natural roosting areas may no longer be available or have been compromised.

The good news is that a lot can be done to support local bat populations. Building a bat box can be a fun and cheap weekend project for families, affording an opportunity to observe and enjoy these animals up-close. Similarly, school educators can introduce bat boxes on school property as an interactive way to engage kids in biology. Bat boxes can even be incorporated into the exterior walls of buildings between wall insulation and exterior finishing material.

While many knowledge gaps remain about the needs of bats in urban areas and how to better support them, it is certain that there are enumerable reasons to support conservation of these winged wonders.

A bat box is installed in the El Yunque National Forest of Puerto Rico
A bat box is installed in the El Yunque National Forest of Puerto Rico. (USDA Forest Service photo)
Category/Topic: Forestry