The persistent buzzing of flies near a person is a common annoyance that signals a fundamental biological attraction. These insects are actively seeking resources necessary for their survival and reproduction. Understanding the specific chemical and environmental cues that draw flies is the first step toward effectively controlling and eliminating them from a personal space.
Identifying the Specific Attractants
Flies are equipped with highly sensitive sensory organs that allow them to detect minute chemical signatures from a distance. The human body constantly emits a cloud of odors that signals a potential food source. Exhaled breath contains carbon dioxide, which is a long-range beacon for many fly species, signaling the presence of a warm-blooded host.
Closer in, the compounds in human sweat provide a direct nutritional incentive. Sweat contains water, salts, carbohydrates, and proteins, which flies can readily “drink.” Lactic acid, a byproduct of physical exertion, and ammonia are particularly attractive organic compounds found in perspiration.
Flies land on skin to lap up secretions, which also contain dead skin cells and the bacterial growth that develops in sweat. They are drawn to a combination of human-produced odors and any trace food remnants on the skin or in the immediate vicinity. The composition of these attractive odors can vary significantly based on an individual’s genetics, diet, and activity level.
Eliminating Indoor Breeding Sites
Flies persistently indoors are often breeding nearby, drawn to sites where they can lay their eggs. The most effective long-term control measure is to locate and eliminate these breeding sources, which invariably involve moist, decaying organic matter. A primary indoor source is often the garbage receptacle, especially for house flies which lay eggs in rotting food.
Garbage should be kept in tightly sealed containers and removed frequently, particularly in warm weather when the fly life cycle accelerates. It is important to regularly clean the inside of trash cans with soap and water to remove any residue or organic film that remains after the bag is removed. This prevents flies from being drawn to the lingering odors and bacteria.
Drain flies breed in the gelatinous muck that accumulates inside sink, tub, and toilet drains. To eliminate them, these drains and traps require cleaning with a wire brush or specialized cleaner to physically remove the organic debris where the larvae develop. Fruit flies are attracted to fermenting materials like overripe produce, spilled sugary liquids, and residue in recycling containers. Promptly disposing of overripe fruit, rinsing containers, and wiping up any spills will remove their food and breeding source.
Immediate Repellent and Exclusion Techniques
While eliminating breeding sites is a long-term solution, immediate relief requires active exclusion and trapping methods. The first step is to ensure that physical barriers are intact, checking all windows and door screens for small tears or gaps. Properly sealing cracks and crevices around doors and windows prevents flies from easily entering the structure.
Simple, non-toxic traps can be highly effective for active indoor control. A popular method for fruit flies involves a mixture of apple cider vinegar and a few drops of dish soap in a small, shallow bowl. The flies are attracted to the fermented vinegar smell, and the soap reduces the surface tension of the liquid, causing the insects to sink and become trapped.
For personal and area repellency, certain essential oils can be utilized to confuse a fly’s olfactory receptors. Peppermint, citronella, lemongrass, and eucalyptus oils are known to deter flies. These oils can be diffused or mixed with water and sprayed around entry points like doorways and windows to create a scent barrier. Additionally, placing a simple fan near a seating area can keep flies away, as the moving air creates an environment that is difficult for them to navigate and land in.