As I often do, I was scouting the interwebs for those who share with me the search-phrase “The Language of Smells”, when I came across this article on the many scents of the deer.
Hunters use the scent of their prey for a variety of effects. It may not come as a surprise that communication for animals is very reliant on Smell (you know, being that they can't talk and all), and that learning their language is of utmost importance to the serious hunter.
Deer in particular have five distinct aromatic compounds each secreting from specific places on their bodies. The tarsal glands are on the inner hind legs and communicate individual recognition as well as dominance and sexual maturity. The metatarsal gland is on the outer hind legs, and is used as an alarm pheromone for some deer, but not all. Interdigital glands are in-between the hooves and used to lay a scent trail making it easier for deer, particularly younger ones, to find each other. The pre-orbital gland is in the front corner of the eyes, and is left behind on branches when a deer has been feeding. Finally the forehead gland is used to rub on trees to communicate dominance and sexual maturity. Don't forget urine, which yields hormonal and dietary information.
For the hunter, scent can be passive or active. Using a “passive scent” of non-estrus doe is meant to relax the deer by saying that other deer are around. Using an active scent like a sexually active signal, at the wrong time of year, can alarm deer because it's ‘just not natural!’