If your camping from somebody, but don't want to be seen though want to know where they are, listen to the sound of footsteps, BUT check your radar quickly to make sure it isn't a friend. Another thing is if you know somebody is coming and they might have spotted you, if you get to high ground but can't see them directly, look for thier shadows and judge where thier head will come up.. pop em in the head then they will be like and you will be like then if it happens to me I will say "OMFG YOU HAXXOR" but you know I'm joking... right?