Although often seen as pests, ants, along with some other insects, are really helpful. So what happens if we put them to good use cleaning up waste in cities?
New research shows that these insects are not only an effective way of cleaning up such waste, but they are also efficient.
The research, done by Dr. Elsa Youngsteadt and others at North Carolina State University, found that insects native to New York City can consume more than 2,000 pounds of food that gets tossed or dropped on streets every year. Those bugs were even hungrier and less picky about what they ate than similar insects in parks. In particular, the pavement ant was one of the most effective foragers of food waste.
But how do you test something like this out? Researchers put food trays at median strips throughout the city. Some of these dishes had open sides for easy access by any scavenger, while others had mesh around them that only allowed entrance to insects. Similar amounts of food disappeared from the trays with mesh than those without, showing that insects eat as much food as larger animals, such as rats.
The beauty of a system like this is that if insects eat most of the food waste, other scavengers stay away from those areas. This is important when considering larger creatures, such as rats, sparrows and raccoons, that often bring disease to city areas.
Even more importantly, the ants were resilient. Even during Hurricane Sandy, insects continued eating up food waste.
"You'd think that several feet of salt water would deter some ants," says Youngsteadt. "But it's good news for urban ecosystems. They're going to stick around and keep doing their thing no matter what— even when a disaster happens."
Researchers repeated their experiment, but this time in parks. However, in an interesting turn of events, park insects were pickier eaters and ate less than their city counterparts.
Food waste is a huge problem in American cities, and its clean up is expensive. The U.S. spent over $11 billion in 2008 on cleaning up this kind of waste, which is about 26 percent of all waste that ends up on the streets.
"If left uneaten-or if eaten by animals that harbor human diseases-this littered food waste becomes a public health, environmental, and financial burden," writes the study authors. "Future work should further explore the conditions that favor the competitive advantage of arthropods as food removers in cities."
It's certainly something to think about, especially when ants turn up in your kitchen. Because of their scavenging, though, perhaps they're keeping worse pests away, such as mice.
[Photo Credit: Reinhold Brezovszky/Flickr]
