Lunging Stance in Drosophila (1 of 2) (video) California Institute of Technology Loading video... Caption Two male flies exhibit the "lunging" behavior that indicates aggression in Drosophila. Lunging consists of a fly rearing up on its hind legs and snapping down with its forelegs on its opponent. Credit Caltech/Liming Wang and Michael Maire Usage Restrictions With credit as given above. 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.