In Michigan we'd use a potato gun (for the noise) to scare them off, as well as very low velocity bb guns (hit the foot of one, they alarm and the flock leaves)

In Michigan we'd use a potato gun (for the noise) to scare them off, as well as very low velocity bb guns (hit the foot of one, they alarm and the flock leaves). The ultimate device to keep those poop machines away was my Australian Shepherd - sending her out to chase kept them away for a day+