Play behavior in animals is a window into emotional wellbeing. Understanding the science of animal play helps us design environments and management systems that support positive welfare states.
Play represents one of the most reliable and accessible positive welfare indicators available to welfare scientists and practitioners. Animals play when they feel safe, have sufficient energy, and experience positive emotional states. Conversely, play suppression is an early and sensitive indicator of stress, fear, or illness. This makes play frequency and quality a powerful tool for welfare assessment in both research and practical husbandry contexts. The science of animal play has also contributed to our understanding of animal emotion: the ultrasonic chirps of playing rats, the lateral leaping of calves in open pastures, the aerial acrobatics of dolphins — these are not anthropomorphic interpretations but documented behavioral correlates of positive affect. Environments that support play support welfare in a deep and fundamental sense.