Why Do Bugs Fly In Your Face?

If you’ve ever been outside on a warm summer evening, you’ve likely had the unpleasant experience of bugs flying directly at your face. This phenomenon can be annoying and perplexing – why do bugs seem attracted to fly towards humans?

If you’re short on time, here’s a quick answer to your question: Bugs don’t actually target faces, but they are drawn to carbon dioxide, heat, moisture, and other cues that lead them towards people. Their flight paths often accidentally take them to fly near eyes, noses, and mouths.

In this comprehensive article, we’ll explore several theories that explain this pesky bug behavior. We’ll look at the role of exhaled carbon dioxide, warmth, moisture, smells, and other factors that influence bug flight paths.

We’ll also bust some common myths and explain why it only seems like the bugs are aiming for your face.

The Carbon Dioxide Hypothesis

How Bugs Detect and Use CO2

Many insects like mosquitoes have special sensory organs called sensilla that allow them to detect carbon dioxide (CO2). These CO2-detecting sensilla are located on bugs’ antennas, mouthparts, and even legs.

When they sense higher levels of CO2, bugs recognize it as a cue that a potential food source – like a breathing animal – is nearby.

Bugs don’t just detect CO2 though – they are able to track CO2 gradients in the air to locate and fly towards areas of higher gas concentration. By orienting themselves towards the source of heightened CO2 emissions, hungry bugs can find hosts to bite and feed on more effectively.

Why Humans Exhale More CO2

Compared to other animals, humans and other large mammals give off way more carbon dioxide with each breath. The average person exhales about 2.3 pounds (1 kg) of CO2 per day! This happens for a few key reasons:

• Bigger body size = larger lungs and more CO2 expelled
• Higher metabolism from large muscle mass and energetic brains
• Less CO2 reabsorption in our winding respiratory tracts

Additionally, the CO2 we exhale lingers around our heads rather than dissipating quickly. With such a strong and concentrated CO2 plume right by our faces, it makes sense why small insects buzzing around pick up on those emissions and fly straight towards the source – our noses and mouths.

Linking CO2 to Bug Flight Towards Faces

Multiple scientific studies have shown blocking CO2 emissions from people’s breath causes way fewer bugs to approach and land on them. For example, in one experiment volunteers had 321 mosquito landings when breathing normally.

But wrapping a bandana around their mouths to filter CO2 cut landings by over 95%!

The evidence clearly connects our heavy CO2 exhalations to insect attraction to our faces. Yet many questions still remain about specifics of this phenomenon according to entomology professor Mark Willis.

Answering those will help scientists exploit bugs’ CO2 sensing to better control pest populations. Maybe one day we’ll even have high-tech masks that make us invisible to mosquitoes!

The Heat and Moisture Hypothesis

There are several theories as to why those pesky bugs seem to constantly fly right at your face. One major hypothesis examines how bugs use heat and moisture to navigate toward hosts.

Bugs Are Drawn to Warm and Humid Areas

Many species of flies and mosquitoes are attracted to the carbon dioxide, warmth, and humidity that humans and other animals produce (1). Your body heat and moist breath create a welcoming environment for bugs looking for their next blood meal or place to lay eggs.

Body Heat and Breath Attract Bugs

Your exhaled breath is warmer than the surrounding air and contains higher amounts of carbon dioxide. This signals to hungry insects that a nice warm-blooded host is nearby (2). Some research finds mosquitoes can detect carbon dioxide from up to 50 meters (about 164 feet) away (3).

In addition to following carbon dioxide plumes, bugs can zero in on the infrared radiation emitted as body heat. Mosquitoes and other insects like ticks and bedbugs have special heat-sensitive receptors that help them find hosts day or night (4).

Flies Have Heat-Sensing Pits

Recent research discovered house and blow flies have tiny heat-sensing organs called “pit organs” located on their heads (5). These pits allow flies to hone in on the infrared radiation given off by warm surfaces.

This helps hungry flies locate potential food sources like garbage cans or picnic spreads.

The Role of Smells

Bugs Detect Odors With Antennae

A bug’s antennae serve an important purpose – detecting odors and scents in the environment. The many sensory receptors on antennae can pick up chemical compounds from sources near and far. When bugs catch a tempting scent like food or a mating partner, they reflexively fly towards it.

Unfortunately for humans, our breath and skin give off distinct smells that attract bugs looking for their next meal. Substances like carbon dioxide, lactic acid, and ammonia act like an irresistible perfume to tiny insects.

Breath and Skin Give Off Distinct Scents

With each exhale, we emit carbon dioxide into the immediate space around us. Mosquitos can detect CO2 from up to 50 meters away! They fly towards the enticing gas, hoping to find a nice blood meal at the source.

Sweat and skin bacteria produce acidic compounds like lactic acid. Gnats and flies pick up on the sharp, tangy odor. They excitedly seek out feet and armpits to settle down for a snack. If only we smelled better!

Trailing Human Scents

Bug noses utilize air currents to follow human aromatic trails. Tiny hair-like receptors on insects’ antennae detect odor molecules suspended in the wind we leave behind. Even while hiking or running, it’s hard to escape determined bugs hot on your scent.

Mosquitos, moths, and sand flies all engage in odor-tracking. The insects rely on this important ability to locate potential food, mates, and breeding grounds. Their incredible sense of smell certainly works against humans trying to evade flying pests.

As the stats show, an insect’s scent-tracking capabilities can be quite impressive relative to its size. Their supernatural sniffing powers explain why bugs manage to fly after humans even over long distances.

It seems bugs will continue buzzing around our heads thanks to their antennae’s acute ability to pick up on smelly chemical compounds we emit. Outsmarting teeny insect noses is no easy feat! The most effective bug deterrents work by neutralizing or masking human odors through scent camouflage.

Busting Myths About Bug Behavior

Bugs Don’t Intentionally Target Faces

Many people assume that bugs purposely fly at human faces, but that notion is simply not true. In reality, bugs do not have the visual capacity or intelligence to intentionally target human faces. According to entomology experts at the Entomological Society of America, bugs rely primarily on scent and heat to locate hosts, food sources, and places to lay eggs.

While mosquitoes and some other bugs can detect carbon dioxide and heat emitted from human breath and faces, allowing them to orient toward people, they do not actually recognize facial features or expressions.

Bugs simply lack the advanced visual systems and brain complexity for detailed visual processing or spiteful behavior.

It’s Not Revenge or Spite – Just Instincts

Another common misconception is that bugs fly at faces as some form of revenge or out of spite when humans try to swat them away or eliminate nests and hives. But in reality, bugs operate almost entirely on pre-programmed instinctual behaviors related to survival and reproduction.

Behaviors like seeking warmth, carbon dioxide sources, places to lay eggs, food sources, and safe harbors are wired into bugs’ nervous systems. They do not have emotions or thought complexity enabling calculated revenge.

So when a bug pesters your face, it is acting on ingrained instincts, not angry payback.

Bug Vision Doesn’t Allow Facial Recognition

Most bugs have compound eyes, which give them very wide fields of vision useful for detecting motion and light levels. However, compound eyes have poor resolution and cannot form sharp images. Very few bug species have advanced enough visual systems to recognize objects or facial features in detail.

As that comparison shows, even bugs with more advanced vision do not have enough acuity or visual processing power to recognize or target human facial characteristics. So while mosquitoes use visual cues to locate hosts, they simply cannot see faces in detail or single them out for intentional bothering.

The Illusion of Aiming for Your Face

Why does it seem like bugs are always flying directly at your face? Here are a few reasons this annoying phenomenon happens:

The Face Sticks Out and Is Warm/Moist

Your face and head are the most prominent parts of your body as you move through the environment. With your face sticking out, it naturally encounters more bugs along the way. Studies also show that bugs are attracted to the warmth and moisture emitted from your mouth, eyes, and nose.

So they gravitate toward your head without actually aiming for it.

We Focus on Bugs That Come Closest

Among the swarms of bugs in the air around us, we notice most clearly the ones that come very close to our faces. Our vision keys in on nearby motion, and when something flies within inches of our eyes we can’t help but track it.

This tunnel vision makes us ignore the majority of bugs not headed straight for us.

Confirmation Bias About Memorable Bad Flies

We tend to remember vividly the occasions a gnat flew right up our nose or a bee buzzed within an inch of our eyes. But we forget the thousands of uneventful bugs passing harmlessly nearby. This confirmation bias causes us to believe bugs target our faces much more than the reality.

The saying “Don’t make a mountain out of a molehill” applies here. Insects are just going about their business and your face happens to be in the flight path by coincidence. They aren’t actually aiming for you, so try not to take it personally! Stay calm and just shoo them away.

Conclusion

As we’ve explored, bugs don’t actually set out to pester human faces. But through their instinctive search for warmth, carbon dioxide, moisture, smells, and other cues, their flight paths often accidentally lead them buzzing around eyes, mouths, and noses.

While having bugs fly near your face can be annoying, understanding their behavior can at least help explain why they act this way. We can also bust myths about bugs holding vendettas or intentionally targeting people.