While cities sleep, creatures of the night swoop through the skies overhead. You may not realize it, but many bat species live in urban areas. People usually don’t notice the animals because they’re nocturnal. By day, bats roost in trees in parks, beneath bridges, and under the awnings of buildings. But “at night, they are active—flying, feeding, drinking,” says Winifred Frick, a biologist at the University of California, Santa Cruz, and chief scientist at Bat Conservation International.
Living alongside people isn’t always easy for wildlife. One problem city-dwelling bats face is light pollution. The electric lighting that illuminates cities at night disorients these creatures, which are used to navigating in total darkness. A brighter nighttime environment can also disrupt their cycle of sleeping and waking, as well as interfere with feeding and reproduction. “Light pollution can change behavior in harmful ways for some bat species,” says Frick. Fortunately, researchers, engineers, and city planners are working together to remedy the problem and help bats reclaim the night.