http://www.digitaljournal.com/science/new-york-s-ants-are-natural-garbage-disposal-units/article/419029

New York's ants are natural garbage disposal units

Posted Dec 5, 2014 by Sravanth Verma
New York's ants could play an important part in the city's garbage disposal process according to new research from NC State University.
Red ant carrying a piece of a black ant  after severing its head.
Red ant carrying a piece of a black ant, after severing its head.
The study looked at the role played by the tiny insects that live in the median strips of Manhattan. These thin grassy enclaves between the city's busy streets house 18 species of ants, a significant fraction of the total of 42 species of ants in the city. The researchers found that these median-strip ants disposed of a greater amount of garbage, the equivalent of 60,000 hot dogs a year in the Broadway corridor alone. Getting rid of all this trash also keeps populations of rats and other larger pests under control.
The team developed wire mesh cages with tiny openings that only ants could enter and placed weight food samples of common foods such as hot dogs, cookies and chips within. Outside the cages, the same process was repeated as a control to check how much was being consumed by the city's other refuse-eaters.
Consumption levels were measured after 24 hours. Research associate at North Carolina State University and lead author of the paper, Elsa Youngsteadt says, "We thought, oh, the parks, with their more diverse species -- that's where we're going to see the ants doing a more thorough job. So we were surprised when the opposite was true." The median-strip dwellers consumed two to three times more than the Central Park dwellers.
"It really underscored for us how important it is to have different kinds and sizes of green spaces around the city," Youngsteadt said.
The study "Habitat and species identity, not diversity, predict the extent of refuse consumption by urban arthropods" was published in Global Change Biology.