The History of Mouse Utopia

John Calhoun conducted the mouse utopia studies at the National Institute of Mental Health, or NIMM. He built the 25th utopia in 1968 and it was a square cube with soft ground up corn cobs on the floor. The population continued to climb until the 19th month when it peaked at 2,200 mice. Things were not as rosy as they appeared however. Because so few juveniles died there were suddenly huge hordes of loser mice with nowhere to go. In earlier utopias involving rats some dropouts resorted to cannibalism.