> Having observed the rats so closely, Calhoun now had a pretty good idea of what was limiting growth. The rats had divided themselves into eleven clans. Four h

> Having observed the rats so closely, Calhoun now had a pretty good idea of what was limiting growth. The rats had divided themselves into eleven clans. Four had burrows conveniently located at the center of the enclosure, near where Calhoun had placed the food bins. In these privileged clans, a few dominant male rats mated with (and protected) a larger number of females. Although the high-status mothers successfully raised many pups, this wasn’t enough to offset the losses in a population that was aging and, increasingly, brawling. > The rats from the banlieues, for their part, lived under constant stress. When they attempted to get to the food bins, the fat rats in the middle tried—often successfully—to repulse them. Along the edges of the enclosure, packs of low-ranking males roamed from burrow to burrow, harassing the females. The outer-burrow females were so exhausted that they rarely conceived, and, when they did give birth, they often abandoned their pups. Not unless there was a group of people who had somehow figured out how to legally steal other people's UBI checks. The rats did not actually have access to infinite food. Some of the rats did, and they figured out how to monopolize that food source and exclude other rats.