PITCH-PERFECT

Bats can find their food in total darkness by using echolocation: they emit 10 to 20 high-pitched beeps per second and listen for variations in the echoes that bounce back at them. Bats are able to hear frequencies ranging between 20Hz and 120 000Hz, compared with a range of 20Hz to 20 000H in the case of humans and 40Hz to 60 000Hz in the case of dogs.