The objective of this study was to investigate the effects of social rank (Experiment 1) and familiarity (Experiment 2) on dustbathing in domestic hens (Gallus gallus domesticus). We conducted choice tests between two conditions using actual birds as the stimuli and evaluated
the effects in terms of quality and quantity of dustbathing performed. Twenty-four, medium-ranked hens were selected as test subjects. The stimuli presented were combinations of a high-ranked hen, a low-ranked hen, or no hen at all for Experiment 1, and a combination of a familiar hen, an
unfamiliar hen, or no hen for Experiment 2. The number and duration of dustbaths, wing tosses as well as other behaviours were measured. For Experiment 1, the test hen performed dustbathing more frequently on the side of the hen, regardless of its social rank, when presented with a choice
of a high- or low-ranked hen, or no hen. For Experiment 2, the test hen performed dustbathing more frequently on the side of the familiar hen when presented with a familiar hen or no hen, and more frequently on the side of no hen when presented with an unfamiliar hen and no hen. It was concluded
that dustbathing was not affected by social rank, and that the quality and quantity of dustbathing was greater on the side of the familiar hen. However, dustbathing was restricted by the presence of an unfamiliar hen.