The thing you need to understand about crows is that they can't see well at night, they don't fly at night, they don't migrate at night ever. So the crows actually can't leave the city physically once it gets dark because they can't fly at night. So they're kind of trapped. If you shoo them away from one block, they're going to go just as far as they have to to feel safe, and then they're going to try to go to sleep again because that's what they're supposed to do when it's dark. What happens is, they get shoved around the city to a different place and there are just as many crows and just as many droppings in the different place. So I'm not a fan.