A Biorobotic Investigation of Norway Rat Pups (Rattus norvegicus) in an Arena

Biorobotics research typically focuses on simulating specific aspects of animal biomechanics, sensory systems, and computational abilities. We have developed a novel methodology for integrating the study of biorobotics and animal behavior. We describe several metrics for characterizing and comparing rat pup and robot behavior without presupposing behavioral goal states. In the rat pup and robot experiments, we found that when 10-day-old Norway rats (Rattus Norvegicus) are placed in an arena, they typically follow walls to a single corner and stay there. However, our thigmotaxic robots followed walls but typically circumnavigated the entire arena, contacting all corners, and exhibiting asymmetric corner behavior. After observing the latter behavior in robots, we found that rat pups also exhibited asymmetric corner behavior. Thus, our robotic experiments, while not quantitatively matching pup behavior, led to the discovery of a previously unrecognized pattern of behavior in rat pups. This illustrates the value of models in leading to discovery of new patterns of behavior in the system modeled. Our results also show that simple thigmotaxic architectures alone may not explain pup behavior in an arena.