Now, to give them a leg up—or a wing up—on these calculations, a new study shows that bats have an innate feel for the speed of sound. [Eran Amichai and Yossi Yovel, Echolocating bats rely on an innate speed-of-sound reference]Yossi Yovel: It has always been assumed that bats use the speed of sound in order to assess distance. So basically, their brains measure time, and then if they know the speed of sound, they can assess the distance to a target using it. Yovel: But this assumes that they know the speed of sound, and this was never actually tested. But Yovel hypothesizes that coming into the world with a fixed notion of the speed of sound is probably a plus.