Moths draped in stealth acoustic cloak evade bat sonar

Amazing stuff!

"Ultrathin sound absorbers offer lightweight solutions from building acoustics to sonar cloaking. The scales on moth wings have evolved to reduce the echo returning to bats, and we investigate their resonant sound-absorber functionality. Resonant absorbers are most efficient at resonance, and laser Doppler vibrometry (LDV) revealed that an individual moth scale’s three resonance modes indeed span the biosonar frequencies of bats.  ...

Here we investigate moth-scale vibrodynamics to understand their role in creating acoustic camouflage against bat echolocation, where scales on wings provide ultrasound absorber functionality."

Moths draped in stealth acoustic cloak evade bat sonar | Research | Chemistry World Moths can hide from the sonar of feeding bats using their acoustically camouflaged wings. Their evolved stealth adaptation is the result of an array of scales attached to their wing membranes that absorb ultrasound frequencies emitted by hunting bats, and are the first acoustic metamaterials found in nature.

Here is the PNAS paper:

Biomechanics of a moth scale at ultrasonic frequencies