One evening, in April 2021, Rachel Siegel was sitting on her living room couch, watching TV with her husband, when she stumbled across a Facebook post about a family of beavers in her suburb of Glenview, Illinois, that was about to be trapped and killed by the local HOA. “It never occurred to me that beavers would be living in a suburb like Glenview,” Siegel says. But there the beavers were, building dens in the banks of the Chicagoland suburb’s stormwater retention ponds. There were six of them, all told—a mother and a father, a yearling, and three kits. All were about to be killed for “doing the things that their instincts tell them to do,” as Siegel puts it, “which is to build dams in our river valleys.”