Did you know that cigarettes take twelve years to decompose on average? That’s a big problem, as they are the most littered item on Earth – every year, approximately 4.5 trillion cigarettes are discarded with little regard for the environment. The new startup Crowded Cities has a plan to rid streets of this type of pollution – and it involves training crows to exchange cigarette butts for food. It’s a well-established fact that crows are one of the smartest animals in the world.