Crowded CitiesThe CrowbarCigarette filters, you find them in the park next to you in the grass, in dirty ditches and under your shoes. What if we could find a way to collect these butts from all corners of our city and precious parks? With crows, that have become perfectly adapted to city life, we can! By training crows to recognize and pick up cigarette filters we can solve this tenacious problem of city pollu
