As children we learn more about life through playing games than we do in any other way. It is the ability to play that enables us to develop into well co-ordinated, adaptable, highly social individuals. But we are not alone, animals play also. For many years this animal play was thought to be somehow ‘different’ to human play, but this is proving not to be the case. Why do animals indulge in play, what are the functions of these energy draining and often dangerous activities? This interdisciplinary programm will explore the reasons that play is so important to development: by describing social, locomotor and object play behavior in animal as diverse as reptiles, birds and mammals, it will find out the benefits it does provide. Finally it will look at the shocking evidence of what happens to young animals who are prevented from playing. In a startling parallel to humans, animal deprived of play, develop into dysfunctional adults, and even serial killers.