The European bat has lowered its voice to evade detection by some moth species, allowing the mammal to swoop in for the kill, new research shows.

To help "see" in the dark, most bats echolocate, sending out sound waves and listening for echoes bouncing off objects, including prey.

(Related: "Early Bats Flew First, Developed 'Sonar' Later.")

Moths with ears—a feature that evolved independently in several moth species—can hear the bat calls and avoid the predators. Some species, such as tiger moths, even use ultrasonic clicks to "jam" a bat's sonar.

Yet one species of bat, the barbastelle, has evolved a whispering counterstrategy to outwit the eared moths—an unusual occurrence in nature, said