Figure 1. Different set-ups to study aggression in Drosophila. (A) Arena with a centrally placed food cup that can contain yeast paste or a virgin female, allowing the videotaping of aggressive behavior.68 (B) Set-up allowing the simultaneous recording of 35 arenas, usually during a 15 min period.72 (C) Scheme of a set-up compatible with CADABRA software allowing automated scoring of lunging, tussling, wing threats and chasing of two pairs of flies simultaneously. This set-up can be expanded to analyze eight pairs of flies simultaneously.67 (D) Set-up allowing the instant analysis of the aggressive encounters between groups of eight flies over a 2 min period.6,12,73