I for one can not tolerate tresspassers. It is one of those fine lines with me and I do not tolerate it. Definitley nip this in the butt somehow with the previous suggestions that everyone has given. I for one would personally go knock on the door and confront them. Next step would be a call to authorities and explain the situation in fine detail in how this keeps happening. They have to do something about it and can not just ignore it. You have a right to hunt there and if its your land your paying the taxes for you and your friends to hunt. Not tresspassers.