THE scene: a pond on a common in south London, long past 10 pm. The players: a group of bat enthusiasts and their guide, squinting into the darkness. “There’s one! Quick, tune to 21 kilohertz,” someone cries. The enthusiasts tune their detectors, which pick up the high-frequency noises and convert them into “smacks”, “tocks”, “ticks”, “chip-chops” and “warbles” that people can hear. The bats come to this pond to drink and hunt insects. The humans come to marvel at these creatures of the night.
Welcome to bat walking, the latest global nature-watching craze. Where there are bats, you’ll likely find…
