What would happen if you built an almost-perfect world, limited in terms only of space? How would people react -- could you create a utopian society? These are the questions John Bumpass Calhoun asked himself during his career as an ethologist, which led him to create tiny 'universes' for rodents... only to find that, time and time again, these perfect civilizations collapsed. Join Ben, Matt and Noel as they delve into the parable of Universe 25 and behavioral sinks.