During the 1960s, America is in turmoil: faced with rising crime, social upheaval, sexual deviancy, and civic unrest, blame increasingly falls on the pressures of overpopulation. The stress of city life is driving everyone mad. Enter John B. Calhoun, an ecologist-turned-psychologist employed by the National Institute of Mental Health to study the effects of crowding on rats. Over three decades, Calhoun builds a series of 'rodent utopias' where every need is met - except space. Jon Adams and Edmund Ramsden's Rat City is the first book to tell the story of John Calhoun and his rodent utopias, culminating in the terrifying world of Universe 25: a rodent habitat where the only strategy for survival is complete social withdrawal. Following the rats from the baiting pits of Victorian London to the laboratories of NIMH, and Calhoun from rural Tennessee to inner-city Baltimore, Rat City explores how his work informed the understanding of personal space, public housing, and debates about the animal urges underpinning human nature in mid-century America - while challenging the popular assumption that Calhoun's deteriorating Rat Cities necessarily predicted a bleak future for humanity. Rat City is an enthralling mix of dystopian science and urban history whose relevance becomes more obvious as societies confront ecological collapse and social unrest in an increasingly crowded world.