Lamanai Archaeological Reserve, Belize“It’s the Vampyrum!” Winifred Frick called out from the darkened trail ahead. The rainforest around us thrummed with katydids, while howler monkeys whooped into the clammy night. As I caught up with Frick at the mist net—a spool of black mesh scientists used to catch bats for study—I looked over her shoulder, and the sight made my heart flutter.

Frick, the chief scientist at the nonprofit Bat Conservation International and an ecologist at the University of California, Santa Cruz, was running point on the nets at this year’s bat survey in Belize. During the past week on this November expedition, I’d seen dozens of bats up close in Lamanai Archaeological Reserve: Wrinkle-faced bats