Mantis shrimp can repeatedly pummel the shells of prey using their hammer-like appendage with the speed of a 22 caliber bullet. They have the fastest punch in the animal kingdom so fast that it creates cavitation bubbles that can injure, stun, or kill their prey even if it wasn’t directly hit by the raptorial appendage. The smasher mantis shrimp will hit many times per day. Mantis shrimp’s club can survive these rapid-fire blows by filtering out certain wave frequencies. This is possible because of the way the club is designed. It contains chitin, which is the same substance found in many crustacean shells, but it’s arranged differently. The helicoidal structure (like a spiral staircase) naturally filters out shear waves, which could be helpful when designing body armor and helmets.