I need to deter deer from my yard using something or some method that can't be detected.?

My neighbor is a hunter and he started attracting deer by feeding them. We live on conservation land and a family of deer have started coming by regularly to eat. He has a camera set up to see exactly what times they come. I don't like the idea of him hunting in our back yards. He will be using a bow and while I don't mind him hunting just not like this. I find it unfair and not a sport.