I would have not beleievd it except for wha ti experienced last week. I was in my Summit . It wa sstill dark and I was totally still. The pig walked within 10 yds of my tree with no wind blowing. It raise dit's snout up in the air and grunted loudly and moved on. I had no the animals could smell ya up in a tree. There fore yeah. They are probably smelling us walking in the woods.
Chuck