Snapping shrimp produce a snapping sound by an extremely rapid closure of their snapper claw. Source levels reported for Alpheus heterochaelis are as high as 220 dB (peak-to-peak) re. 1 µPa at 1 m distance. The loud snap has been attributed to the mechanical contact made when the snapper claw contracts. The recent ultra-high-speed imaging of the snapper claw closure at 40500 frames per second has revealed that the sound is, in fact, generated by the collapse of a cavitation bubble formed in a fast flowing water jet forced out from between the claws during claw closure. A temporal analysis of the sound recordings and the high-speed images shows that no sound is associated with the claw closure, while a very prominent signal is observed during the collapse of the cavitation bubble. Gallery of Fluid Motion Award-winning entry 2001