In the wild, organisms generally allocate their time among many behavioural tendencies in response to both current and anticipated motivational requirements. However, activities that are apparently 'irrelevant' often intrude, either during conflict between these behavioural tendencies, or when a strong tendency is thwarted. These 'irrelevant' activities are called displacement behaviours and are widely documented in the ethological literature. We report here that an experimental analogue of displacement behaviour in the rat depends upon the integrity of the mesolimbic dopaminergic projection to the nucleus accumbens septi, olfactory tubercle and associated structures of the forebrain.