I learned a lot about critters nose from moose hunting. Granted moose have better smell than deer, but while in Newfoundland, we would sit there in black spruce totally hidden watching moose over 150 yards away. We watched them sitting there feeding for 20 min while the wind was in our favor. It suddenly changed and swirled and went right for them. And those moose looked like someone shot them. They actually winded us 150yards away. Thats impressive.