sciencehabit quotes a report from Science.org: Whales sing, orcas squeal, and sea turtles croak. But sharks are more the strong, silent type. Now, researchers report the first evidence that sharks make sounds, too, described today in Royal Society Open Science. The animals may be making the sounds — a series of clicking noises — by snapping their flat rows of teeth, which are blunt for crushing prey. The sharks can hear mostly low-frequency noise, and the clicks they emit are higher pitched, which suggests they are not for communicating with other rigs. It’s possible they are a defensive tactic. Marine mammals that eat rigs, such as leopard seals, can hear in the frequency range of the rig clicks, but the researchers question whether a few clicks would deter an attack. The sounds might be part of their response to being startled, the team says.