Movie 1

Part 1: A fly standing on a glass coverslip and stimulated with wide-field visual motion. Non-flying flies do not show stabilizing gaze responses to triangle-wave wide-field motion, although they do show sporadic head movements.
Part 2: An intact fly suspended in the flight arena, but not flying, while stimulated with wide-field visual motion. Wingless flies do not show stabilizing gaze responses if they are not attempting to fly. “Flight” or “non-flight” states were determined by observing the fly's wings and halteres; this fly's legs are not retracted and its halteres are stationary.
Part 3. A wingless fly attempting to fly while stimulated with wide-field visual motion. Wingless flies show stabilizing gaze responses when they are attempting to fly. The moving (blurred) halteres and retracted forelegs indicate attempted flight.