The District of Columbia consistently makes the top five list of America’s rattiest cities, a problem made worse by warming winters, a rising population, and outdoor dining areas made permanent after the Covid pandemic. Now, some people are fighting back. A group of local dog owners patrol the city's alleys, using their dogs to sniff out and kill rats. "It’s primitive but very effective," says Teddy Moritz, a breeder taking part in the Saturday night rat hunt. For businesses, however, there's another solution: cats. Blue Collar Cats is a program that allows business owners take in a street cat to act as a rodent deterrent. "It's a fantastic twofold benefit of having the cat here, everyone loves seeing her. She's performing a real job. We don't need her to actually save of money, but she really does," says Tim Williams, director of operations at a gardening center with a mice problem.