Sweden Trains Crows to Collect Cigarette Butts and Help Clean City Streets

Cities around the world spend enormous amounts of money trying to keep their streets clean. Among the most stubborn forms of litter is the cigarette butt, a tiny object that millions of smokers casually flick onto sidewalks each day. Individually they seem insignificant, but collectively they form one of the largest sources of urban waste. In Sweden, where environmental awareness is often strong, the scale of the problem still surprises many people. Research cited by the Keep Sweden Tidy Foundation estimates that more than one billion cigarette butts are discarded on Swedish streets every year. These small pieces of waste make up roughly sixty two percent of all litter found in public spaces.

In the city of Södertälje, just outside Stockholm, officials have been experimenting with an unusual response. Instead of relying solely on street cleaners and municipal workers, they have explored a partnership with an unexpected workforce. The city has been testing a pilot project in which wild crows collect cigarette butts and drop them into a special machine. When the birds deposit the litter into the device, it releases a small food reward. Over time, the crows learn the connection between the discarded trash and the reward waiting inside the machine.