To mitigate the increasingly out-of-control rat epidemic in Brooklyn, city officials let opossums loose in public parks and underneath the Coney Island boardwalk, so that the opossums could maim, eat, and kill the rats, before dying off themselves. But that sick plan failed: Not only did the rats outrun the predators, continuing to thrive in buildings and parks, but now Brooklyn residents are frustrated with all the opossums — sharp-toothed, foul-smelling, conniving creatures — that are plundering garbage cans, running around golf courses, and eating the local fruit trees. Some are even rabid! “They are everywhere,” said Theresa Scavo, chairwoman for the Sheepshead Bay community board. So consider this a lesson for New York in general: In an opossum-eats-rat world, everyone loses.