Frog-eating bats are using every possible cue to track frogs, right down to the ripples in the water made by the frog's movement when it calls.  Dr. Mike Ryan, a professor of zoology at the University of Texas, Austin and Research Associate at the Smithsonian Tropical Research Institute in Panama, and his team - led by post-doctoral researcher Wouter Halfwerk - studied the tiny ripples made in the water by the vibrating throat-pouch of the Tungara frog when it makes mating calls. Bats listen for the calls, but when the frog detects a bat, it will stop calling. The ripples that the call makes, however, propagate through the water for several seconds after the call ends, and bats can echolocate these tiny disturbances and use them to find their prey.

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