Amy Savage recently conducted an experiment in Manhattan. Savage is a postdoctoral scholar at North Carolina State University; she was investigating the roles that non-human animals provide in taking food from urban environments, an ecological task she calls "food removal service." For the experiment, Savage and her fellow researchers laid out hot dogs, cookies, and potato chips—anthropogenic foods that have nothing to do with any evolutionary history of eating, except yours and mine—to see what would happen.
"In the most urban environments we sampled, the medians on Broadway, arthropods moved just as much food as all the vertebrates combined," she says. Rats of New York, set that crown on the ground: It was New York's ants who did the lion's share of the cleanup.