As disease devastates bat populations, they also face a host of other threats, from pesticides to habitat loss. Here’s how to help in your own backyard.

They inhabit the ruins of a 14th-century empire in Africa, cling to 800-year-old cliff-side dwellings in Arizona, forage in old Indian temples and European churches, and occupy the decidedly less grand crawl spaces of our modern homes.

As the only true flying mammals, the world’s 1,300 bat species know how to get around. While some have esoteric lifestyles—roosting in unfurled banana leaves or tents carved from rainforest foliage—many are less specialized, building a life wherever people have already made their mark on the land. Now adapting to the latest artifacts of human empire, bats often trade their traditional caves and trees for abandoned mines and cozy attics.

Though resilient, these animals—who account for a quarter of all mammal species—are in decline worldwide. The pace of development is much faster than it was in the days of ancient temple-building, with chainsaws destroying natural roosting sites, pesticides decimating food supplies, and wind turbines killing bats outright. Humans have even learned how to take to the skies themselves, their long-distance flights paving the way for the speedy transport of pathogens like the one that has killed nearly 7 million bats in North America in the past 10 years.

The fungus responsible for white nose syndrome likely arrived on the clothing or gear of cavers, scientists or other visitors to hibernation sites. Not known to affect bats where it originates in Europe, here the pathogen causes bats to awaken too early from winter slumber, depleting their limited fuel reserves. Transmission is so rapid that little brown bats could be gone from the eastern U.S. by 2020.

“In just a couple of decades, we’re looking at going from an extremely common species to an endangered or nearly extinct species,” says Rob Mies, a bat expert and former executive director of the Organization for Bat Conservation. White nose syndrome will likely affect more than half of the 47 bat species in the U.S. and Canada. “For us bat biologists, it’s just absolutely devastating.”

Their vanishing would be ecologically disastrous. Most bats are insectivorous, consuming up to 120 percent of their weight daily and contributing an incalculable amount of insect control services.

Some are pollinators, fruit eaters, and seed dispersers, playing an important role in forest regeneration and even in happy hours.  “When you go to a Mexican restaurant and you order chips and guacamole and a margarita, those things aren’t going to exist without bats,” says Mies. “Bats pollinate avocado trees, and they also protect corn—they’re one of the most important predators of the corn earworm moth. And they’re the only pollinators of the agave that we make tequila from.”

While certain locations—like the Congress Avenue Bridge in Austin, Texas—are known for harboring these quiet creatures of the night, bats are everywhere; we just don’t realize it. “When people are outside and bats are flying over their head, they don’t know they’re bats,” says John Griffin, director of the HSUS urban wildlife solutions program. “They think they’re birds.”

More closely related to whales than birds, bats can see but primarily rely on echolocation, emitting high-frequency sounds to find prey. Their wingspans belie their size; even a big brown bat is not so big at all, weighing less than an ounce, notes Deborah Robbins Millman, who was the director of the Cape Wildlife Center in Massachusetts when a special facility was built for the animals. Bats are so diminutive that staff feed them with tweezers and wear special gloves to protect both the handlers and the bats’ paper-thin wings.

In a retrofitted barn attic situated near night lights to attract insects, recovering bats at the Cape facility also feed themselves. Before the habitat was built, “we had one bat who was literally walking to the food dish,” says Millman, but now flying patients can build cardio strength critical to life in the wild. “We’re really bat-happy here. People are afraid of them, but they do a lot of good.”

Follow these tips to create safe spaces for these delicate creatures on your own property:

Plant a Bat Garden.

Masters of disguise, bats don’t reveal daytime whereabouts; red bats hanging from trees look like decaying leaves, Indiana bats blend into loose bark of dead and dying trees, and hoary bats’ coats mimic lichen. To help them evade predators and find roosting opportunities, leave tree snags in place and plant hickories, maples, oaks, spruces, pines, beeches, gums, and other species that will provide many nooks and crannies in the bark and trunks.

Bats eat moths and other nocturnal fliers attracted to flowers that open at sunset, such as evening primrose, or blooms that never close, such as wild bergamot. In many regions, fall is a great time to plant; find lists of recommended species, a bat garden planting guide, and bat habitat signs from the Save Lucy Campaign.

Install a Bat Hotel.

Even if designed according to building codes specified by experts, a bat house may sit empty for years. But when an ice storm topples the preferred real estate of dead ash trees down the road, your hospitality will be well-received. “Bats aren’t going to leave a perfect place,” says Mies, “but when they need to relocate, that’s when the bat house is available.” Create your own backyard bat house with these helpful blueprints and guidelines.

Evict Humanely.

Tiny crevices leading to attics are invitations to bats. “They can virtually flatten themselves and get into really tight spaces,” says Griffin. To remove them safely, he covers gaps with a temporary fiberglass window screen open at the bottom. Called a “check valve,” the method allows bats to exit but not reenter; once they’re gone, openings can be sealed. For more information about humane eviction and exclusion methods, visit the websites of Bat Conservation International and the Humane Society of the United States.

The original version of this article was published in All Animals magazine. Featured image of Rodriguez fruit bat: Alfred Viola, Northeastern University, Bugwood.org.