On a hot June night, revelers descend on Washington's Adams Morgan neighborhood, a nightlife and dining hotspot in the U.S. capital. But they aren't the only ones profiting from the good weather.

Also out in number are the city's rapidly growing population of rats, which prowl the alleys behind the restaurants, bars and clubs, feasting on leftovers tossed out in the trash.

The rodents' merrymaking comes to a swift halt amid a flurry of barks, gnashing teeth and splattered blood: the result of a hunt involving a dozen humans and their hounds out on a weekly "ratting" expedition.