Urban ants, some of New York City’s tiniest inhabitants, are trash-eating, rat-fighting machines, according to a new study.
Researchers from North Carolina State University found that colonies of the arthropods living in the city’s streets and parks eat thousands of pounds of discarded junk food and keeping populations of rats and other pests at bay in the process.
The researchers said that the ants that live in the medians of the city’s thoroughfares are particularly helpful. Along Broadway alone, researchers said, ants ate about 2,100 pounds of junk food -- the equivalent of 60,000 hot dogs -- in less than one year.
"This isn't just a silly fact," said Dr. Elsa Youngsteadt, the author of the study. "This highlights a very real service that these arthropods provide. They effectively dispose of our trash for us."
Youngsteadt said that researchers came to their conclusions after putting out measured samples of junk food in street medians and city parks during 2012 and 2013. Some samples were put in cages that only ants could access, while others were put in the open so other animals could eat them. Researchers left the food out for 24 hours and then came back to see how much the ants had taken.
It found that the ants in the medians took the most junk food, eating two to three times what park ants consumed.
They found that food in open areas was also picked at by other city-dwelling species, like rats and pigeons, but the ants ate enough food to keep other animals away.
"This means that ants and rats are competing to eat human garbage, and whatever the ants eat isn't available for the rats," Youngsteadt said. "The ants aren't just helping to clean up our cities, but to limit populations of rats and other pests."
Researchers say they were also surprised to see many of the ants weather Sandy, which struck during the middle of their study. The storm had no measurable impact on the ants’ food consumption, even though many of the areas where the study was conducted had been flooded with brackish water.