NATIONAL MUSEUM OF NATURAL HISTORY

Real Bats Are Superheroes Too

They might not wear capes, but these mammals have superpowers to spare


A bat hangs upside-down on a thin branch during the day. Green leaves line the frame of the photo.
From pollination to powerful poop, these much-maligned animals give us plenty to be thankful for. Ameya Khandekar

Batman returns to theaters this week for the latest installment in his quest against evil. But for those of us outside of Gotham City, the true heroes are the animals he’s named after.

“There are whole ecosystems that depend on bats,” said Ingrid Rochon, museum technician in the Division of Mammals at the Smithsonian National Museum of Natural History. “They come in so many different and beautiful varieties,” each with a role to play in its habitat.

As bat populations plummet in the face of hazards like the devastating disease known as white-nose syndrome, it’s becoming increasingly clear that we’re losing vital members of the world’s ecosystems. Here are five reasons bats deserve superhero status, even if they don’t have their own theme song.

They’re pest-control pros

Batman’s alter ego Bruce Wayne may be a billionaire, but real bats could give him a run for his money, Rochon said. Researchers have estimated that bats provide billions of dollars’ worth of pest-control services to the agricultural industry in the United States alone.

That’s because they gobble up insects like nobody’s business. Take the little brown bat, one of North America’s most common species. “They can eat up to half their body weight in insects every night,” Rochon said. “And a single colony of big brown bats, which is about 150, can eat over a million insects in a year.”

Since many of those insects are agricultural pests, like plant-eating beetles and moths, bats protect crops ranging from corn to grapes and pecans. They make their mark far beyond farmland, too, by dining on city pests like termites and mosquitoes. They’re such efficient predators, according to one study, that declines in bat populations due to white-nose syndrome likely mean that hundreds of tons of insects now go uneaten every year.

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The fungal infection white-nose syndrome is thought to have killed millions of bats in North America. The disease, shown here in a little brown bat (Myotis lucifugus), spreads among bats, but humans can also transport it between caves on clothing or equipment. Marvin Moriarty, U.S. Fish and Wildlife Service

They help plants multiply

While most bat species chow down on insects, others prefer nectar or fruit. As they flit from plant to plant, coating their fuzzy faces in pollen or swallowing — and then expelling — seeds, they’re moving the ingredients for new plants far and wide.

That makes them crucial pollinators, just like bees and butterflies. “Especially in places where there aren’t a lot of insects, like deserts or mountaintops, bats are pollinating the plants there,” Rochon said. “And they travel farther than insects, so they’re spreading pollen over a greater distance.”

In fact, more than 500 flowering plant species depend on bat pollination to reproduce. These include a number of species that are economically and culturally important to humans, like the agave plant and the towering saguaro cactus.

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Many plants rely on bats as their main pollinators. Here, a Mexican long-tongued bat feeds on nectar from an agave plant, which is used to make tequila. U.S. Fish and Wildlife Service

They inspire invention

Given bats’ aerial acrobatics and their talent for navigating at night, researchers have long thought these animals might be able to teach us a thing or two. They’re superstars for engineers working on biomimicry — the development of nature-inspired solutions to human problems.

Bats attract much of that admiration because they’re incredibly skillful flyers. Thanks to the complexity of their wings, they can dart around obstacles, soar at remarkable speeds and even land upside-down. That’s fascinated scientists, since it could offer a model for more effective flight in human-made machines.

Bats are also experts at echolocation. They send out high-pitched pulses of sound, which bounce off the objects around them and return to their ears. Based on how those sounds are reflected back to them, bats can get a handle on their surroundings — allowing them to cruise through the air even in complete darkness. They’re so good at it that researchers have turned to bats as inspiration for self-driving cars, low-light navigation systems and tools for people with visual impairments.

They sustain cave communities

Dark, dank and isolated, caves might not seem like the most hospitable places. And while it’s true that they typically don’t harbor as much life as other habitats, they’re home to surprisingly rich communities of species — thanks, in large part, to bats.

“They’re getting nutrients from outside the cave, and they’re bringing them into what would otherwise be a barren environment,” Rochon said. “If the bats weren’t there, the cave would have no life.” Bats emerge from the caves, devour their dinner and return to their roosts, where they leave droppings packed with crucial nutrients like potassium, nitrogen and phosphorus. That waste feeds microbes and insects, which then feed larger cave dwellers like salamanders.

In short, Rochon said, “There are entire cave ecosystems that are built on a foundation of bat poop.”
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Many species of bats congregate in caves, hanging upside-down in close quarters. Their nutrient-rich waste serves as the basis of cave food webs. U.S. Geological Survey

Their refuse is revealing

Bat poop — or, more officially, guano — has plenty to offer for humans, too. For one thing, the fact that it’s chock-full of nutrients makes it a highly effective fertilizer. Research also shows that guano could serve an entirely different purpose: helping us reconstruct Earth’s past.

To understand what the planet’s climate looked like far before humans were keeping reliable records — or before they were around to keep them at all — scientists turn to archives in nature, known as proxies. Tree rings, ice cores and the fossils of deep-sea organisms can all tell us about their surroundings at the time they formed. They’re time capsules, documenting things like temperature, rainfall and atmospheric chemistry from the distant past.

As it turns out, bat guano could be something of a gold mine in this respect (if not in others). Researchers have studied the composition of bat poop deposits in caves, accumulated over thousands of years, to get an idea of what temperature and precipitation looked like as those bats were doing their thing. In other words, one bat’s trash is a climate scientist’s treasure.

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