Here are 10 fascinating facts about ravens. In France, people believed ravens were the souls of wicked priests, while crows were wicked nuns. In Sweden, ravens that croaked at night were thought to be the souls of murdered people who didn’t have proper Christian burials. These flocks of young birds live and eat together until they mate and pair off. Scientists have found higher levels of stress hormones in teenage raven droppings than in the droppings of mated adults.