Just how the moth developed such a defense is unclear. It doesn’t know about the world of sound and can’t be striving for anything one way or the other. A vast cascade of lucky accidents?
Their fuzz works like an acoustic panel to cut down the noise volume from their movements. From ScienceDaily: While some moths have evolved ears that detect the ultrasonic calls of bats, many types of moths remain deaf. In those moths, Neil has found that the insects developed types of “stealth coating” that serve as acoustic […]