Freezing and Escape in Response to An Overhead Shadow (video) Cell Press Share Print E-Mail Loading video... Caption A single fly walks back and forth, and briefly grooms, before a shadow moves overhead. The fly jumps and freezes in place, its wings and other appendages held motionless. After about 5 seconds, the fly suddenly breaks its freezing posture, and escapes. Credit William T. Gibson Usage Restrictions Credit Required. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.