Deer fly tape is a sticky patch, typically about 3 by 6 inches, that adheres to the back of a hat or cap to trap deer flies as they land. It works because deer flies almost always attack from behind, targeting the head and shoulders. When a fly lands on the patch, it gets stuck and dies. It’s a surprisingly simple solution to a pest that resists most conventional repellents.
How Deer Fly Tape Works
The patches use a pressure-sensitive adhesive on one side, similar to flypaper but designed to be worn. You peel off a backing strip and press the sticky side outward onto the back of a baseball cap, sun hat, or hard hat. As you walk, hike, or work outdoors, deer flies that approach from behind land directly on the adhesive instead of your skin. Some people finish a walk with a dozen or more flies stuck to a single patch.
The reason this low-tech approach works so well comes down to deer fly behavior. Female deer flies (the ones that bite) are visual hunters. They’re attracted to movement, warmth, carbon dioxide from your breath, and dark or shiny surfaces. When they zero in on a person, they typically circle behind and aim for the highest point: your head. A sticky patch placed on the back of a hat sits right in their landing zone.
Why Repellents Don’t Work Well on Deer Flies
Most people try deer fly tape after discovering that DEET-based sprays and other chemical repellents do little to stop deer flies. Unlike mosquitoes, which detect you primarily through chemical cues and can be confused by repellents, deer flies rely heavily on visual signals. They spot you from a distance based on your movement and silhouette, then close in fast. A chemical barrier on your skin may deter a mosquito that lands and probes, but a deer fly commits to biting almost immediately, often before the repellent has any effect.
This is what makes physical trapping methods more practical. The fly doesn’t need to be deterred from biting. It just needs to be caught before it gets the chance. Researchers at Michigan State University Extension have noted that sticky hat patches “work pretty well” based on field testing, and they remain one of the most commonly recommended tools by entomologists for personal deer fly protection.
Getting the Most Out of Deer Fly Tape
Placement matters. The patch should go on the back of your hat, centered and as high as possible. If you wear a wide-brimmed hat, place it on the crown rather than the brim, since flies aim for the top of your profile. Some people use two patches, one on the back and one on top, for heavier infestations.
Color plays a role too. Deer flies are drawn to dark colors and shiny surfaces, which is why they swarm around dark hats, wet hair, and even swimming pools. Wearing a light-colored hat gives the sticky patch more contrast and may reduce the number of flies that land on uncovered parts of your clothing. The University of Kentucky’s entomology department recommends light-colored clothing generally to reduce biting fly annoyance.
Each patch lasts for one outing in most conditions. Dust, pollen, and debris will eventually coat the adhesive and reduce its stickiness. In heavily wooded or dusty areas, you may need a fresh patch partway through a long hike. Most products are sold in packs of four to twelve for this reason.
Where and When You Need Them
Deer flies are a warm-weather problem, most active from late spring through early fall depending on your region. They breed near water, so areas around lakes, streams, marshes, and wooded wetlands tend to have the worst populations. Peak activity is during daylight hours, particularly on warm, sunny, low-wind days. Overcast or breezy conditions reduce their activity somewhat.
If you garden, fish, trail run, or do fieldwork in these environments during summer months, deer fly tape is worth keeping in your pack. The flies are aggressive enough to follow you for hundreds of yards once they’ve locked on, so simply walking faster rarely works. A sticky patch lets you keep moving without stopping to swat.
DIY Alternatives
Commercial deer fly patches are widely available online and at outdoor retailers, but some people make their own. The simplest method is wrapping a strip of tanglefoot (a sticky insect barrier sold at garden centers) around the outside of an old hat. Others apply double-sided carpet tape to a hat’s surface. These homemade versions work on the same principle, though the adhesive may not hold up as long or trap as effectively as purpose-built patches.
Another common DIY trap is the “trolling” method: attaching a blue Solo cup coated in sticky adhesive to the top of a hat. The blue color attracts deer flies even more aggressively than dark fabric alone, and the cup’s shape gives them a larger landing surface. This looks ridiculous but can catch dozens of flies per outing in high-population areas. Some outdoor workers in the upper Midwest and Southeast swear by it for long days in the field.
Limitations to Keep in Mind
Deer fly tape protects your head and neck effectively, but it won’t stop every bite. Flies occasionally land on arms, legs, or shoulders, especially if you’re standing still. Combining a sticky patch with light-colored, long-sleeved clothing and a hat with a full brim gives the best overall protection. Protective mesh jackets designed for biting flies can also help in areas with extreme populations.
The patches also won’t reduce the deer fly population around your property. They only catch the individual flies that target you on a given outing. For broader population control near homes, large-scale traps like the Manning trap or similar designs that use dark moving targets to lure and capture flies in bulk are more effective, though they require setup and maintenance that a hat patch obviously doesn’t.