I know its not very predictable. But remember one thing when setting a trap in front of a dirt hole, or scent post.......they will ALWAYS come in to the set with their nose in the wind. Our winds here are predominately W NW in the winter. So, I try to make make my sets where the trap is E SE of the hole/backing. ALso, when I have traps available, I make two sets around the expected path of travel. One set on the up wind side, and one on the down wind side. That way if they don't see the set, they will likely smell one of the two regardless of the wind direction. Use the wind as your corral.