In 2022, in Södertälje, near Stockholm, a startup called Corvid Cleaning had an idea that sounded like science fiction: teaching wild crows to clean the streets.
Christian Günther-Hanssen, its founder, designed a machine that dispensed a little food every time a crow dropped a cigarette butt inside. No cages or forced training: the crows took part of their own free will, drawn by the reward. And it worked, because these birds reason almost like a seven-year-old child.
The fact that made the story go viral is staggering: in Sweden, more than a billion cigarette butts are thrown away every year, accounting for 62% of all street litter. Günther-Hanssen estimated savings of up to 75% in cleaning costs if the method expanded. But here comes the twist that few people know: the municipality never turned the pilot into a permanent program, and in 2025 the company declared bankruptcy. A brilliant idea that, for now, remained just that.