Trappers are divided as to their views on "Human Scent and Sign". Some of the old and experienced ones think there is nothing to either for as they say they catch the shrewdest animals without any trouble. This is true but the trapper of years of experience knows how to set his traps without leaving "sign."
There is no question but that the shrewdest animals "look" with suspicion upon "sign" or anything out of the ordinary especially at their den or places where they often frequent.
COYOTE TRAPPING ON THE CATTLE RANCHES.
The hunter knows that deer, bear, fox and other animals rely upon their sense of smell as one of their ways to evade them. Is it not as reasonable that they smell a trapper when on his rounds?
Of course after the trapper has made the set and gone, his scent will gradually leave and the "sign" is probably the cause of the animal keeping away, should it continue to do so.
That human scent is quite noticeable to animals is proven from the fact that bloodhounds can follow a man's trail or scent even tho it has been made hours before. Yet after a day or so the scent is lost and the best bloodhound cannot follow it.
Do not the same conditions apply to the scent left by the trapper when setting his traps for wolves, foxes, mink, otter, beaver and other keen scented and shrewd animals? It surely does, and after a few days, at the farthest, the "human scent" is all gone.
This being true, then it must be the "sign" that keeps the animal away. Again, it may be that the animal has had no occasion to return.