Tony O’Neill is a vegetable growing expert with over 40 years of growing experience, a Watch Manager with South Wales Fire and Rescue Service, and the author of 19 books on vegetable growing, soil health, and composting. His book Simplify Vegetable Gardening reached No.1 on Amazon’s international bestseller list and received the GardenComm Silver Laurel Media Award in 2025. He is the creator of Simplify Gardening, one of the world’s most widely followed vegetable growing platforms with 455,000 YouTube subscribers and 1.4 million monthly views, and the founder of GrowTrack Systems Ltd, the company behind the AI-powered garden intelligence system GrowTrack. Read more at tonyoneill.com.
The carbon dioxide you breathe, your fruity deodorant, or your yellow t-shirt makes you super attractive to adult fungus gnats. During their short seven-day lives, procreation is prime, and they’ll soon find out you’re not “it,” but you sure resemble their typical egg-laying environment.
What Do Fungus Gnats Find Attractive?
Adult fungus gnats are obsessed with reproduction; it’s hardwired into them. In a mere seven days, they must mate while flying in a swarm and then find an optimal environment where they can lay their eggs.
The optimal egg-laying environment exudes carbon dioxide, smells earthy, and can be yellow(ish).

Why Carbon Dioxide Appeals to Fungus Gnats
Carbon plays a crucial role in soil health due to its capacity to form several bonds (four per atom) in many intricate organic structures.
Soil respiration (releasing carbon dioxide from the soil) results from decomposing organic matter and plant litter by soil microbes, plant roots, and soil fauna.
It is an important indicator of soil health because it measures the level of microbial activity and the content and decomposition of organic matter. It also reflects the condition of a soil’s chemical and physical environment.
The presence of carbon dioxide (CO2) tells the female fungus gnat that the environment will be healthy for her larvae and that there will be ample fungi, the larvae’s primary food.
Why Fruity Smells Appeal to Fungus Gnats
A healthy soil smell is reminiscent of rain falling on parched ground. The scent is called petrichor and is a product of actinomycete activity in the soil, and their process produces an alcoholic compound called geosmin.
Even humans can smell a very diluted concentration of geosmin, but for the fungus gnat, it’s almost overwhelming. The smell lets them know there is very healthy microbial activity below – an ideal place for egg-laying.

Fun Fact: Petrichor, a term coined by two Australian soil scientists in the 1060s, combines the Greek words petra (stone) and ichor (referring to the golden fluid in the veins of immortals).
Also, fungus gnats associate fruit with water and healthy soil, another attractive prospect for a future home for her precious larvae and pupa offsprings – the future fungus gnat generation.
Why The Color Yellow Appeals to Fungus Gnats
Yellow is the color of straw and the sun. Other than that, I have no idea why they love yellow.
I know they do, and if you stick some yellow sticky fly trap cards up, the general theory will be proven.
Suppose you’ve got an infestation problem; the card strategy works. Flytrap cards are yellow for a purpose, and fungus gnats (and house flies) love it enough to get in a sticky situation.
A product called Gnat Stix (a sticky yellow card) is generally available online and at nurseries. Simply place the adhesive cards beneath the pot’s canopy to trap fungus gnats.
The gnats will become stuck in the sticky area as they move near the yellow card, which helps prevent females from laying eggs. A more straightforward solution is to eliminate the eggs and larvae in the soil using 1-to-4 hydrogen peroxide (3%).
Can I Remedy Fungus Gnat’s Attraction to Me?
Stopping the eggs from hatching will stop larvae development and is the best way of getting rid of fungus gnats. Interrupting the life cycle before adults emerge is the best way to be free of harmless yet frustrating adult fungus gnats.

You will continue to experience the discomfort of adult fungus gnats if you don’t take aggressive measures to eradicate these insects sometime during their transformation stages in the soil.
I don’t advise you to make yourself less appealing – basically, you will need to stop breathing.
Why it’s Important to Deal with Fungus Gnats
The life cycles of fungus gnats can continue indefinitely, with overlapping generations, in warm indoor environments with ordinary or high humidity.
When female fungus gnats search for a damp growing medium inside, they can spread to other plants and infest them by riding on plants, plant pots, and soil. Examine any plants you bring home from the store, as gifts, or from an office environment.

Summarizing Why Fungus Gnats Fly In Your Face
Carbon dioxide is a fungus gnat aphrodisiac, so when they’re in your vicinity and you breathe their favorite smell out, they’re on you like white on rice. The same goes for fragrances and the color yellow.
Failure to proactively fight these insects in their early development stage means you’ll keep dealing with the nuisance of adult fungus gnats.
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Why do gnats bite my ears.?
Gnats often swarm around ears because they’re attracted to warmth, moisture, sweat and the carbon dioxide you breathe out. Your ears and face give off all of that. Some tiny biting gnats also go for thin, exposed skin, which makes ears an easy target. If they’re bad in your area, a fan, light repellent, or avoiding still damp areas at dusk helps a lot.