A good olfactory sense is a deer’s best defense. Hunters have known this for thousands of years, but for the last two decades, a revolution led by science has changed the way we hunt deer from coast to coast.

Hunters see only a fraction of the deer. Odor lingers long after a hunter has passed. Deer that cross his trail are alerted. The hunter might hear the warning blows or snorts that are the signal that a deer has caught his scent, but by then it is too late.

When a deer inhales, it can identify and sort a complex array of odors, some are food or herd smells, some are warnings. Deer also communicate by means of scent signals that include pheromones.

Tarsal, metatarsal, preorbital, interdigital, forehead, nasal, preputial and caudal glands secrete scent information. A specialized organ in the roof of the deer’s mouth is thought to help a buck determine a doe’s timing and may synchronize the reproductive physiology of the buck.

Does can pick out their fawns by scent, bucks stake out territory and advertise for does during the rut and the readiness of the doe is activated by scent detection.

Jim Heffelfinger, Regional Game Specialist with the Arizona Game and Fish Department and adjunct professor with the University of Arizona, Tucson has made a living out of studying ungulates and game birds. In his book, Deer of the Southwest, he described a deer’s olfactory attributes. A deer’s nasal passages “are lined with a tissue (epithelium) that contains mucus-producing cells. These cells maintain a moist environment in the nasal cavity to aid in the collection of scent. When a deer inhales, it draws in airborne molecules that land on an area of moist nasal lining, and through a chemical reaction, messages are sent to the brain for identification of the scent.”

Temperature and humidity play a role. Cool weather and the increased humidity of autumn improve a deer’s sense of smell and make a highly tuned scent detection system that much better.

Our challenge in October is to beat a deer’s defenses and we have varying degrees of success based on our implementation of strategy and tactics. We succeed more often when we employ a holistic, no-nonsense approach to scents.


Scent can be covered up to some degree, confusing a deer’s ability to sort through other odors and detect the human threat, but a better approach is to control human scent prior to the application of covers and attractants.

Studies have indicated that deer can process up to seven different smells at the same time. That means a deer can smell you as well as the product you trust to cover your scent. By eliminating degrees of human odor, we diminish the scent carried downwind and spread through swirling breezes.

Human scent is carried on clothing and equipment. It emanates from gun oils and fabrics; it is manifested on hatbands and the soles of our feet. Every step we take to block or eliminate scent is a small victory.

The battle begins with the body. A daily shower or a simple sponge bath with unscented soap makes a big difference.

Cooking smoke is another hazard. In our camp, we change clothes before we make dinner. The next day’s garments are kept in bags where they don’t pick up camp smells.

Odors cling to clothing from the inside as well. Scientists have engineered fabrics that focus on odor removal or stop them from forming. One approach is the use of nanotechnology.

In the past, clothing companies treated the textiles after they were woven. Today, they can introduce treatment elements much earlier in the process. Some companies are using silver to fight odor. And they’re able to embed the element at the primary level.

The process infuses a silver ceramic polymer in their soft, breathable base layer fabric which binds to the bacteria in perspiration. With the fabric close to the skin, backcountry hunters can limit the odors they exude even after long, sweaty hikes.


Once the hunter understands that washing might not be good enough, the goal becomes odor removal. Gear Aid's Mirazyme Odor Eliminator utilizes a natural blend of microbes to remove bacteria that causes odor. In fact, Gear Aid makes a number of products that attack odor at the source. Getting ready for a recent hunt in which we had to walk in to ground blinds, I employed Gear Aid's ReviveX Pro Cleaner and the Rubber Boot Saver.

Clothing companies have been blending a silver antimicrobial agent into clothing to fight odors. Now, from Outgo, there's a microfiber towel with silver ions in the fabric surface. The ions are activated in the presence of undesirable bacteria.

The technology is out there that can reduce our odor signatures. We may never completely control the scent we bring to the woods, but the more we reduce our own odor, the better our odds of seeing deer.

Gary Lewis can be reached at www.garylewisoutdoors.com.

Originally Published: Jun 23, 2015

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Mirazyme Odor Eliminator

Mirazyme Odor Eliminator