This is Scientific American’s 60-Second Science. I’m Karen Hopkin.Bats use echolocation to hunt for their meals, and moths are often on the menu.But in the acoustic arms race between predator and prey, moths also have a trick or two up their sleeve―or, actually, on their wings.Because a new study shows that moth wings are covered with scales that absorb sound, particularly the ultrasonic variety preferred by bats.So moth and butterfly wings are covered in layers of scales.These are made of a naturally occurring polymer called chitin, which is a polymer you find in most insect and crustacean exoskeletons.That’s Thomas Neil of the University of Bristol.He started out by bombarding bits of moth wings with sound and seeing what bounced back.We discovered that moth scales actually resonate in response to being hit with ultrasound.And they resonate at frequencies that pretty much perfectly match the frequencies that bats use for echolocation.That vibration converts sound energy to mechanical energy, which muffles the echo that gets back to the bats.That probably hasn’t happened by accident, that these scales are such a shape and size that they’re resonating at just the right frequencies that they can absorb sound energy from hunting bats.Next, Neil and his colleagues modeled the sound-dampening capabilities of an array of different scales.The really cool thing about moths is their scales are all different shapes and sizes.
