How do they know

[deadeye]

I always wondered how a deer knows when to stop so as to leave a tree between themselves and the hunter. Last Saturday I watched this small buck who occasionally stopped to sniff or inspect his surroundings.  I pretended he was a big bucks and looked for the best standing shot. Every time he stopped, there was a tree blocking his vitals. I often wondered just how they know when to stop. 

[Steve-o]

A deer may walk straight to you from a long way away after you call.  But have you ever seen it where they somehow seem to put a tree between themselves and the location where the sound came from (me) so you can't see the deer until they get close?  I've had this happen twice.  (That I know of.)