If this POKéMON is flying by fluttering only a pair of wings on either the forelegs or hind legs, it's proof that CROBAT has been flying a long distance. It switches the wings it uses if it is tired.
Sapphire:
CROBAT sneaks up on its intended prey using wings that barely make a sound. This POKéMON rests by hanging on a tree branch with its rear legs that serve as wings.
Fire Red:
The development of wings on its legs enables if to fly fast but also makes it tough to stop and rest.
Leaf Green:
It flies so silently through the dark on its four wings that it may not be noticed even when nearby.