Washington DC deploys cat army against rats

Feral cats are just one kind of animal that some cities are embracing for their rat-killing prowess. In New York City, a group of rat-hunting terrier, dachshund, and mutt owners patrol the streets. Chicago has even given urban coyotes an uneasy embrace. For the most part, these animals aren’t part of official city programs, but unofficially, most cities are game for whatever kills rats. The question is how much help they can offer. “My position [on the cats] is if it works, that helps us,” says Gerard Brown, who manages the DC city government’s rat control program. Rat calls to the city hotline are up by a third over the last three years, which Brown attributes to a string of mild winters. “Usually when winters are cold, that acts as a natural exterminator,” he says. In 2016 Mayor Muriel Bowser responded to the growing complaints by declaring a renewed war on rats. There are two basic ways to kill off a rat population. One is to limit rats’ food supply, which in cities means garbage. Ecologists would call this a bottom-up approach, cutting off the base of the food chain. There’s also the top-down approach: introduce a predator, whether human or feline, to kill the rats.