The aggressive behaviour rhythm ofBandicota hengalensis under different social conditions were studied in the laboratory. The number, intensity and duration of aggressive behaviour peaks varied depending on the number, sex and social status of the interacting conspecific /s. Significantly the peaks of aggression were recorded during the dark period. In heterosexual conflicts both sexes were equally belligerent. However in male interactions with more females, the former emerged dominant always. Similarly one male dominated another in male-male encounters. Confrontation amongst several males in the presence of female indicat ed the existence of onlyalpha andomega males.