Robots offer new possibilities for investigating animal social behaviour. This method enhances controllability and
reproducibility of experimental techniques, and it allows also the experimental separation of the effects of bodily
appearance (embodiment) and behaviour. In the present study we examined dogs’ interactive behaviour in a problem
solving task (in which the dog has no access to the food) with three different social partners, two of which were robots and
the third a human behaving in a robot-like manner. The Mechanical UMO (Unidentified Moving Object) and the Mechanical
Human differed only in their embodiment, but showed similar behaviour toward the dog. In contrast, the Social UMO was
interactive, showed contingent responsiveness and goal-directed behaviour and moved along varied routes. The dogs
showed shorter looking and touching duration, but increased gaze alternation toward the Mechanical Human than to the
Mechanical UMO. This suggests that dogs’ interactive behaviour may have been affected by previous experience with typical
humans. We found that dogs also looked longer and showed more gaze alternations between the food and the Social UMO
compared to the Mechanical UMO. These results suggest that dogs form expectations about an unfamiliar moving object
within a short period of time and they recognise some social aspects of UMOs’ behaviour. This is the first evidence that
interactive behaviour of a robot is important for evoking dogs’ social responsiveness