Flies in a backyard are a common nuisance, often consisting of house flies, blow flies, or fruit flies seeking food and breeding sites. Managing this issue requires a multi-pronged strategy that addresses both the source of the infestation and the current adult population. Eliminating flies permanently depends less on killing the adults and more on disrupting their rapid life cycle, which can progress from egg to adult in as little as seven days under warm conditions. A successful approach integrates sanitation, active eradication, and environmental modification to make your outdoor space inhospitable to these pests.
Eliminating the Primary Attractants
Long-term fly control begins with sanitation to remove materials where flies lay eggs. Female flies are drawn to decaying organic matter, such as fermenting fruit, animal waste, and garbage, which provides an immediate food source for their larvae, known as maggots. Since a single female house fly can lay hundreds of eggs, removing these breeding sites is the foundational step in fly management.
Pet waste should be removed immediately, as it is a prime location for fly reproduction. Fallen fruit or neglected garden debris should also be cleared promptly before it ferments and attracts flies.
Outdoor garbage cans are a major attractant and breeding ground, especially if food residue collects inside. Ensure all trash cans have tight-fitting lids that seal completely, preventing flies from entering. Regularly cleaning the cans with a hose and disinfectant eliminates residual organic matter and odors. Eliminating areas of standing water is also crucial, as flies need moisture and utilize damp surfaces for feeding and breeding.
Active Eradication Methods
Once breeding sites are controlled, the focus shifts to reducing the existing adult fly population using trapping and chemical methods. Liquid bait traps, which use a putrescent, foul-smelling attractant, are highly effective for catching large numbers of house and blow flies. Place these traps strategically along the perimeter of your yard, ten to fifteen feet away from patio areas or entry points you wish to protect.
Proper placement maximizes a trap’s effectiveness without drawing flies toward gathering areas. In warmer temperatures, traps work better in shaded areas to prevent the bait from drying out. Sticky fly traps or UV light traps should be placed where flies commonly rest, such as near doorways or windows. UV light traps must be positioned away from competing light sources to ensure the UV emission remains the primary attractant.
For a residual effect, outdoor surfaces where flies rest can be treated with a residual insecticide. Products containing active ingredients like lambda-cyhalothrin or deltamethrin leave a long-lasting chemical barrier. Apply this treatment to surfaces such as exterior walls, fences, and the outside of garbage bins, where flies land frequently. The insecticide should be applied until the surface is wet, but re-treatment will be necessary after significant rainfall.
Deterrence and Environmental Modification
Making your backyard environment physically unwelcoming to flies is the final component of a control strategy. Strategic use of fans is one of the simplest and most effective non-toxic methods for keeping flies away from outdoor dining and seating areas. Flies are poor fliers, and the turbulent air current created by a fan disrupts their flight patterns, creating an invisible barrier they struggle to cross.
Certain plants act as natural deterrents because they emit volatile oils and scents that flies find repulsive. Incorporating plants like basil, mint, lavender, or rosemary around your patio can help discourage flies from lingering. The natural compounds in these herbs, such as camphor and thymol in basil, release a localized repellent scent.
Another simple modification involves using visual deterrents, such as hanging clear plastic bags filled with water and a few shiny pennies. This folk remedy works because flies possess complex compound eyes highly sensitive to light and movement. The water-filled bag acts as a prism, refracting and reflecting light, which disorients the fly’s vision and causes it to fly away. Screening outdoor food preparation and serving areas is also a practical modification that prevents flies from landing on food during mealtimes.