Just like in other species of animals, some ants might love junk food more than others.
A team of scientists looked at ant populations on the streets of Manhattan, and found only some have developed a taste for human food, North Carolina State University reported.
"We wanted to learn more about why some ant species are able to live alongside us, on sidewalks or in buildings, while other species stay on the outskirts of human development," said Clint Penick, lead author of a paper on the work and a postdoctoral researcher at NC State. "This could also help us determine which species are doing the most to clean up our trash."
To make their findings, a team of researchers looked at over 100 ant samples encompassing 21 species. These samples were collected from 21 different street medians and parks around the New York City borough. The researchers were able to analyze the ants' diets by looking at the isotope content of their bodies.
All animals incorporate carbon found in their food into their bodies, this allows measurements of specific carbons to determine the diet of a human or animal. Carbon-13 is associated with grasses, such as sugar cane and corn. Since most human foods in America contain some form of sugar cane or corn, ants that have a taste for these foods tend to have higher levels of carbon-13. The findings showed ants that lived on sidewalks and medians had the highest levels of carbon-13 when compared with those that lived in parks.
"Human foods clearly make up a significant portion of the diet in urban species," Penick said. "These are the ants eating our garbage, and this may explain why pavement ants are able to achieve such large populations in cities."
The ant Lasius cf. emarginatus, which only appeared in NYC about five years ago and can be found on street medians, did not appear to eat human food. These ants are believed to get their food from foraging along the trees of the city streets.
The findings were published in a recent edition of the journal Proceedings of the Royal Society B.
