This Tech Note column appeared in the December 2020 issue as "Cut the Clutter." Subscribe to Discover magazine for more stories like this.
One rainy night in March 2007, graduate student Ralph Simon found himself alone in the Cuban rainforest. He was following a hunch, based on a picture he’d seen in a magazine. He was after a specific dish-shaped leaf, which belonged to the native Marcgravia evenia vine. The leaves looked like they’d be ideal for reflecting sound, and Simon suspected they would efficiently lure bat pollinators to their flowers in the dark. His adviser was skeptical without proof, so there Simon was, sitting among the creepy crawlers with his infrared video camera and a stash of snacks, waiting for the bats to come. And come they did, several times an hour, for the entire night.
In the years since, Simon — now a sensory ecologist at the University of Antwerp in Belgium — has returned to this same spot at least three more times to gather leaf specimens and test how sound ricochets off them to attract bats. These days, though, he’s using his knowledge to develop technologies that help robots navigate with sound.