Bats.

Again looking at sound, this time a more natural approach, Bats are blind and only fly at night, by the sound of it pretty useless creatures of flight, but fortunately due to millions of years of evolution bats have developed a technique called Echo location.

Echolocation, also called biosonar, is the biological sonar used by several kinds of animals. Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects. Echolocation is used for navigation and for foraging (or hunting) in various environments.