Table 1. Modules of aggressive behavior in male and female Drosophila.

Male	Female
Retreat
Walking, flying or running away	Walking or flying away
Approach/turn toward
Walk toward the opponent while lowering body	Turn/walk toward the opponent
Wing threat
Raise both wings to a 45° angle toward opponent (> 1s) Flicks wings at 45° angle while facing away from opponent	Raise one or both wings to a 45–90° angle toward opponent (< 1s)
Lunge
Rear up on hind legs and collapse on opponent	Rear up on hind legs and collapse on opponent
Shove
Not observed	Thrust the torso toward the opponent with both forelegs extended without recoil
Thrust with a wing threat
Not observed	Thrust and lift one or both wings to a 45–90° angle (< 1s)
Head butt
Not observed	Thrust the torso toward the opponent and strike the opponent with the head; usually followed by recoiling of the torso
Fencing
Fencing (low): extend one leg and tap opponent’s leg Fencing (high): extend leg forward and push opponent facing each other	Fencing (low): Extend leg and contact the opponent in a normal standing posture Fencing (high): Stand tall on the middle and rear legs and contact the opponent with the forelegs (can be combined with a wing threat < 1s) Fencing and feeding: Extend the middle or rear legs and contact the opponent while feeding Fencing threat: Extend the middle legs without contacting the opponent
Chasing
Run after opponent	Not observed
Holding
Grasp opponent with forelegs and try to immobilize	Not observed
Tussling
Tumble over each other, sometimes leaving food surface	Not observed
Boxing
Rear both up on hind legs and strike the opponent with forelegs	Not observed

Ethogram describing the observed modules of aggressive behavior in male and female Drosophila. The listed modules include threat, attack and retreat behaviors. Some of these modules are used by both sexes or show only subtle differences, while others are sex-specific.