Mantis shrimp are known for packing a powerful punch. With the force of a .22 caliber bullet, these colourful invertebrates can smash shells without hurting themselves. Curious to better understand this pelagic pugilist, researchers from Northwestern University in Illinois believe they’ve worked out just how these fascinating creatures can withstand the intense shockwave created by their own deadly strike. “The mantis shrimp is known for its incredibly powerful strike, which can break mollusk shells and even crack aquarium glass,” said Northwestern’s Horacio D. Espinosa, the study’s co-corresponding author and an expert on bio-inspired material, who co-led the study. “We found it uses phononic mechanisms – structures that selectively filter stress waves,” said Espinosa. “This enables the shrimp to preserve its striking ability over multiple impacts and prevent soft tissue damage.” What this means, is that the mantis shrimp’s dactyl clubs are, in fact, covered in specially evolved layered patterns which selectively filter out sound. By blocking specific vibrations, these patterns then act like a shield against self-generated shockwaves.