How Do Bats Navigate in the Dark?

About 70% of bat species (over 1,000 species) use echolocation for navigation and hunting. The bat emits rapid ultrasonic pulses from its mouth or nose, which bounce off objects and return as echoes. The bat brain processes the time delay (distance), frequency shift (Doppler effect — prey movement), and intensity differences between ears (direction) to construct a remarkably detailed three-dimensional model of its environment. Resolution is extraordinary: some species can detect objects as thin as 0.06 mm (a human hair) and distinguish between different insect species mid-flight. Horseshoe bats use constant-frequency calls and rely heavily on Doppler shifts, while vesper bats use frequency-modulated sweeps for detailed ranging. Call rates increase dramatically during prey capture (the "terminal buzz"), reaching 200 pulses per second. Some moth species have evolved ears that detect bat echolocation, enabling evasive manoeuvres — an evolutionary arms race spanning millions of years.