Crowded Skies (E03)

This episode features a creature that creates sound out of thin air with the world's fastest courtship display and arguably the world's most aggressive bird. In a South American jungle, there's 'hunt and evasion' flying during the night, as bats and moths fight for the upper hand in one of the world's oldest arms races. Plus a camera films a giant flock to unlock the secrets that keep half a million birds from colliding in the same air space. (BBC)