The hot dog is a New York staple. But we are not the only ones who like a sausage in a bun. Armies of ants do a very important job – they clean up food litter left by messy eaters of hot dogs, cookies and potato crisps.
In fact, ants and other arthropods on Manhattan’s Broadway and West streets can remove food litter equivalent to the weight of about 60,000 hot dogs or 600,000 potato crisps in a year
The US spends an estimated $11.5 billion annually on cleaning up rubbish. Large cities dispose of about 10 kilograms of litter per person per year. This means the contribution of ants to keeping the streets clean is “modest but notable”, the authors say.
Elsa Youngsteadt from North Carolina State University in Raleigh and her colleagues placed three commonly dropped foods – potato crisps, cookies and hot dogs – at dozens of sites in Manhattan’s parks and islands of greenery between lanes of traffic.
Arthropods removed as much as 59 per cent of the food within a day. More food was eaten at traffic islands than in parks, even though parks were more biodiverse. This may be down to the pavement ant, which lives in big colonies and likes these islands.
“Recycling is among the least glamorous of ecosystem services provided by arthropods, and this was a great study highlighting both its magnitude and importance,” says May Berenbaum of the University of Illinois at Urbana-Champaign.
Such findings could be useful for urban policy and planning, says Harini Nagendra of Azim Premji University in Bangalore, India. “Most of us have seen ants laboriously lugging away fragments of a potato crisp or a cookie, but they have certainly not featured much in discussions about how to manage food waste in our cities,” she says.