Flies are a common nuisance that many people have experienced. The buzzing sound they make hovering around your head can be irritating and difficult to get rid of. But why do these insects linger around people? Experts have provided detailed explanations.
According to a report from Live Science, entomologists from the University of Kentucky state that flies may be attracted to humans for various reasons based on their species. Some flies are interested in humans because we, as warm-blooded mammals, provide a source of food for them. Similar to mosquitoes and deer flies, they are drawn to the carbon dioxide we exhale when we breathe.
Entomologist Jody Gangloff-Kaufmann from Cornell University explains that flies can easily locate humans because we emit scents that they are naturally attracted to, such as carbon dioxide, lactic acid, and carboxylic acids.
However, these specific scents vary from person to person. Assistant Professor Sammy Ramsey from the University of Colorado Boulder points out that if you could see the scents, you would see a bubbling cloud around everyone. These scents are based on your genetics, diet, and daily activities, making some individuals more appealing to flies than others.
The sweat and skin oils of humans contain carbohydrates, proteins, and various substances that flies can consume by licking them off. They simply need to glide their sponge-like mouth over the surface and swallow, allowing them to quickly feed on a variety of nutrients.
Although some flies do absorb nutrients from human skin, these are usually minimal, and flies primarily supplement their diets with salt intake through the consumption of sweat. When foraging for food, flies are more likely to feed on human foods.
While some fly species, including houseflies, prefer decomposing matter, they are not picky eaters and will consume almost anything. To break down solid food, these flies regurgitate digestive enzymes to liquefy the food and then use their straw-like mouthparts to suck it up.
There are over 110,000 known species of flies worldwide, each with unique sensory systems for finding food sources, with variations even between individuals of the same species and different genders.
Many flies rely on antennae or fine hairs on their bodies to detect specific scents. These sensory cells can detect food from miles away and send signals to the brain based on chemical substances found in the air.
If flies detect a scent they like, they will fly closer and land on it. They have taste receptors on their feet to quickly determine if something is edible.
Flies also have compound eyes made up of thousands of independent crystals that are extremely sensitive to movement and provide nearly 360-degree vision. Many flies use visual cues to search for food and escape danger.
Houseflies, in particular, can be annoying because of their innate curiosity, constantly buzzing around you. This natural curiosity also makes them perfect vectors for spreading diseases like cholera, tuberculosis, and typhoid.
While there is no universal method to reduce attractiveness to all fly species, wearing long-sleeved clothing and using insect repellents such as DEET or citronella oil can help deter some flies, according to Gangloff-Kaufmann.
In a previous report, Jordan Foster from “Fantastic Pest Control,” a pest control company in the UK, shared two natural methods to repel flies. One is using essential oils like peppermint, eucalyptus, lavender, and lemongrass for their strong scents, while the other is planting lavender, mint, and marigolds, as the scents of these plants also keep flies at bay.