I think you are way off base here. You have no idea how lucky you are just to be able to spend time in the woods with your grandpa. I wish I could! However, if this is going to be an issue for you and your dad, maybe purchasing some box blinds might be a good solution. They are safe for your grandpa, help a little with scent, and you will always know where he is. Just some ideas, but I think the best is to just the man enjoy being in the woods.