Deer blow,snort what ever you call it when ever they are alerted by something hunter or other critter's, when they snort what they are doing is cleaning out there nasal passages then they smell for new info on trying to figure out what you are deer rely on their sence of smell and hearing, wait until they are behind you and you either didn't hear them or you dozed off and they snort you can climb a tree in less than 2 second's.......good luck