Can Deer Smell Thermacell Mosquito Repellent?

If you’ve done any early season hunting for deer, then you’ve most likely experienced the single most significant downside to the early season: bugs. And by bugs, I mean mosquitoes, flies, gnats, chiggers, and my favorite, ticks. While each of those insect species can be a problem for hunters during the warmer weather, I find mosquitoes to be the most annoying.

Although there are several different approaches to dealing with bugs during the warm weather hunting season, one of the more common questions I’m asked at my day job has to do with hunting deer with a Thermacell. The specific question is: Can deer smell Thermacell or the Thermacell mosquito repellent?

As an avid bowhunter, I’ve tried or tested almost every bug repellent/deterrence product on the market (and a few homemade ones) in an effort to get some relief while not spooking the deer. Some worked better than others, and some flat out didn’t work at all, and some appeared to be an issue for the deer.

However, for the purposes of this post, I’m going to be focusing on the Thermacell mosquito protection product and whether or not it spooks deer.

Before I get too deep into this topic, it’s essential to be familiar with this Thermacell product.

What is a Thermacell?

Thermacell is the brand name of a company that specializes in airborne-based bug deterrence products. They offer insect deterring devices in various sizes, including portable models that can be carried on a person. The first Thermacell product was introduced in 1999, and the company has been growing ever since.

Most Thermacell products are powered by a butane cartridge that creates an airborne deterrent designed to keep certain insects away. The active ingredient in the repellent is a chemical called Allethrin, which is an artificial copy of a natural bug deterrence found in chrysanthemum plants. It’s also worth noting that Thermacell does not use the DEET chemical as part of their chemical deterrence.

In addition to personal bug deterrent devices, Thermacell expanded its product line to include larger-sized bug repelling models designed to offer a larger area of repellent coverage. The personal deterrent devices creates a 15-foot radius of protection, while some of the bigger units feature a wider Thermacell radius zone of protection.

When Thermacell first hit the market, they only offered their chemical mats in a single version (called the original). They have since added a second mat option called “Earth Scent,” which was explicitly geared towards hunters. Thermacell markets the Earth scent mat as being able to mask the scent of human odor, but I am not convinced that it actually masks or covers human smells.

How does a Thermacell Work?

Most Thermacell units consist of three parts:

• Butane fuel cartridge
• A mat that has been treated with the chemical deterrent
• A product body that houses all the parts and operational controls.

When the butane fuel cell is turned on and ignited, it creates heat that is pushed towards the mat housing the repelling chemical. The heat activates the repelling chemical in the mat (which are also called repellent pads) and disperses it in the air. As the airborne product disperses from the device, it drives most flying insects (especially mosquitoes) away.

Having used a Thermacell when hunting for several years now, I can attest to its effectiveness on mosquitoes. In addition, I’ve always found it seems to work on flies, gnats, and those microscopic biting bugs that some call “no-see-ums.”

Using a Thermacell for Hunting

Regardless of the specific Thermacell product and repellent mat that is used, a Thermacell unit does produce a smell, and whitetails will potentially be able to smell that scent. However, there are many factors that play a role in their ability to pick up the Thermacell scent, including:

• Height of the tree stand, or deer stand
• Wind direction
• Thermal drafts
• Your scent control efforts

Plus, the Thermacell chemical is heated as it exits the unit, and hot air rises.

The bigger question is: how do deer react to the scent or smell emitted by a Thermacell unit?

Understanding a Deer’s Sense of Smell

A deer’s sense of smell is one of its main lines of defense against predators and threats, which is why deer have an olfactory bulb that is 4-5 times larger than that of a human.

To put that data in context, take a look at the number of olfactory receipts of the following species:

As a whitetail picks up these different smells or scents, biologists believe that the animal’s brain associates the smell in groups such as danger, food, other animals, etc.

Human scent is associated with danger and typically evokes a flight response. Over the years, I’ve had the chance to witness a deer’s immediate response to human scent many times for different reasons. In some cases, I didn’t adhere to my standard scent control measures or simply forgot a cover scent or scent eliminator product. In other cases, the wind shifted direction and gave me away.

Once, I was sitting in a stand during archery season, watching a decent buck head down a trail straight towards me. Then, the wind direction changed, and he froze in place about 60 yards out. He lifted his head up, testing the air, stamped his foot, blew loudly, and bounded off the way he came. I can only assume that he picked up my scent and associated it with danger.

It’s also important to understand that no matter how well you do scent control, there is simply no way to completely eliminate all the different potential scents that are generated by the human body, including:

• Breath
• Sweat
• Body odor
• Saliva

The best that a hunter can do is consider aggressive scent control measures to eliminate as many foreign smells as possible.

The Smell of a Thermacell vs Deer

Given the fact that humans can smell the odor, a deer can obviously detect the scent as well. So the question really becomes, does a Thermacell scare deer away?

If you do any internet research on that topic, the opinioned answers to that question seem almost split down the middle. I’ve read and spoken to hunters saying that it does spook deer, and I’ve spoken to many reporting that deer are not bothered by a Thermacell.

However, some deer and bear hunting guide services will not allow a Thermacell to be used on hunts.

Here’s my personal take on the topic:

While I don’t have an issue using a Thermacell for most types of hunting, I prefer not to use one while deer hunting. My reasoning is this: since scent control is already an issue for most deer hunters, why add another potential scent control issue to the mix?

To be clear, I have previously used a Thermacell while hunting deer and saw many deer with a Thermacell in use. However, those instances could have been situations where the wind or thermals may have been working in my favor (either upwind or downwind), or I was hunting from a box blind.

Even though I have seen deer using Thermacells, I am not entirely comfortable saying that it did or did not cause a scent issue for me. However, I should also point out that I’ve become a big proponent of scent control and go to great lengths to reduce my smell going into the woods for deer. For example, I usually take the following scent control preventative steps for a hunt:

• Bathe in non-scented soap and use non-scented deodorant.
• My hunting clothes (including boots) are stored in an airtight bag with a charcoal filter. And I mean everything I’m wearing on that hunt.
• My boots are only worn in the woods and then removed at the end of the hunt. They are not worn on any surface other than the woods floor.
• Bows, rifles, calls, rattle bags, and other gear are treated using an ozone-based ionizer, and then a cover scent is applied.

I have other scent control or cover techniques I like, but those are probably best saved for another post.

Since there really isn’t any hard or concrete data that I’ve seen yet saying that deer cannot smell the Thermacell scent or that it doesn’t scare them off, I prefer to use a bug suit instead of a Thermacell to avoid any potential scent issues.

Obviously, as a hunter, you are best served to evaluate the pros and cons of using a Thermacell while hunting deer and make your own decisions.

One last point: I’ve also used a Thermocell for other warm weather hunting, including a turkey hunt and for  hunting hogs.

FAQS

Can you deer hunt with a Thermacell?

Many deer hunters count on a Thermacell unit for bug protection while chasing bucks and does. However, a Thermacell unit does create a smell or scent that deer can smell.

If you’re a proponent of controlling or eliminating your scent as much as possible, then I’d probably skip the Thermacell and look at other bug repellent methods.

Thermacell vs bug spray while hunting deer

While both Thermacell and bug spray are effective options to repel mosquitoes and fly’s, both give off an noticeable smell. Even so-called odorless bug spray has a definite smell that the human nose can detect. If a human can smell the odor, then a deer can most definitely pick up on that scent as well.

How a deer interprets the smell is the real question. If deer associate the smell with danger, then your hunt is potentially ruined. However, if they aren’t sure what to associate it with, or if it doesn’t make them nervous or skittish, then it may not adversely impact your hunting.

Does Thermacell work on ticks?

This question causes some confusion as Thermacell offers a product specifically made for tick control, but it’s a tube-based product that is applied to the yard.

The more popular Thermacell units for repelling bugs DOES NOT offer any protection from ticks. Their airborne insect repellant is designed to repel flying bugs, including mosquitoes, flies, gnats, etc.