Flies are a common nuisance that can quickly infest homes and businesses if left unchecked. Their ability to detect food and breeding sites from great distances makes them expert invaders. Understanding what attracts flies the most can help prevent infestations and allow for better control.
Smells That Attract Flies
Flies have an incredible sense of smell and can detect odors over long distances. Some of the strongest fly attractants are:
Decaying Organic Matter
Rotting food, animal waste, garbage, and compost heaps are among the strongest fly attractants. Flies feed on decaying organic matter and can smell it from far away. Fruit flies in particular reproduce in the moist film found on rotting fruits and vegetables. Ensuring proper food storage, frequent garbage removal, and compost containment will help reduce flies.
Fermenting Sugars
Flies seek out sugary substances like nectar, syrup, alcohol, and fruit juices which provide carbohydrates. Yeasts ferment the sugars, producing carbon dioxide and aromas that signal prime feeding sites for flies. Screens on windows and doors should be used to prevent flies from entering areas with fermenting sugars.
Grease and Fatty Acids
Grease residue and fatty acids from cooking contain volatile organic compounds that flies can detect. Buildup of these substances on surfaces in kitchens and outdoor cooking areas will attract flies. Regular cleaning with soaps, detergents, or disinfectants helps eliminate fatty acids.
Ammonia from Urine and Feces
Flies detect even small amounts of ammonia from urine, feces, and sweat which signals ideal breeding conditions. Proper cleaning of diaper pails, litter boxes, and animal pens is important. Fly tapes and baits should be used around pets.
| Strong Fly Attractants |
|---|
| Decaying organic matter |
| Fermenting sugars |
| Grease and fatty acids |
| Ammonia from urine/feces |
Visual Cues That Attract Flies
In addition to smell, flies rely heavily on visual cues when searching for food and breeding sites:
Dark Silhouettes
Flies are particularly attracted to dark silhouettes which signal potential hiding spots and mating sites. Clutter, garbage bags, and dark corners of rooms should be eliminated. Light-colored surfaces are less attractive to flies.
Shiny Objects
Flies gravitate towards shiny objects like glass, metals, glossy papers, and smooth coatings. It is thought flies mistake these for water surfaces. Minimizing glassware and metallic surfaces helps avoid interest from flies.
Bright Colors
Flies see bright yellows, blues, and greens very well. Items like ripe fruit and pops of color from garbage bags and containers can draw in flies from a distance. Solid, darker colors are preferable for food coverings and waste bins.
Moving Objects
Movement stimulates curiosity in flies, luring them closer to investigate potential prey or mates. Fans, plants blowing in wind, pets, and people stimulate fly activity. Keeping items stationary removes a visual stimulant.
| Visual Fly Attractants |
|---|
| Dark silhouettes |
| Shiny objects |
| Bright colors |
| Moving objects |
Ideal Fly Breeding Environments
Flies need specific environments to breed successfully:
Warm Temperatures
Flies thrive in warm conditions between 60-90°F. Garbage storage areas, compost heaps, and manure piles exposed to sun create optimal temperatures for fly larvae development. Proper containment and frequent emptying prevents heating.
Moist Environments
Eggs and larvae require moist substances like compost, manure, rotting vegetation, and food waste to mature. Wet mops, leaks, condensation, and pet bowls attract flies looking for breedings sites. Fixing leaks, cleaning up spills, and emptying water dishes removes moisture.
Cracks, Crevices, and Holes
Flies seek protected spots with darker conditions to lay eggs and develop. Damage around windows, door jambs, cracks in walls, gaps in flooring, and openings in dumpsters provide harborage sites. Sealing openings denies access to voids.
Undisturbed Sites
Flies need undisturbed areas to breed successfully away from predators. Inside voids and wall spaces, under furniture, in pile of trash, and corners of sheds or barns offer sanctuary. Routinely cleaning all areas forces flies into the open.
| Ideal Breeding Environments |
|---|
| Warm temperatures |
| Moist substances |
| Cracks, crevices, holes |
| Undisturbed sites |
Common Fly Attractants by Species
Some products and substances attract specific types of flies:
Fruit Flies
Fruit flies target ripe and rotting fruits, vegetables, and fermenting foods high in yeast. Overripe produce, spilled beer and wine, vinegar residues, and trash cans contain their favorites.
Drain Flies
Drain flies breed in the gelatinous gunk that builds up inside drains and pipes. Their food source is microbes and fungi in the organic matter. Wet areas under sinks provide ideal habitat.
Phorid Flies
Phorid flies thrive on moist decaying material. They are strongly attracted to odors from urine, feces, rotting meat and eggs, and dead animals. Pet accidents and spoiled food under appliances draw them in.
Blow Flies
Carrion and feces attract blow flies. Dead animals, garbage cans, and poorly maintained compost heaps provide ideal breeding spots. Meat markets, livestock barns, and kennels are prone to infestations.
House Flies
House flies feed on any warm-blooded animal feces including pets, livestock, and humans. Garbage, manure, and sewage attract them. Any moist, organic materials can support breeding.
| Fly Species | Attractants |
|---|---|
| Fruit Flies | Ripening produce, fermenting foods |
| Drain Flies | Gelatinous buildup in drains and pipes |
| Phorid Flies | Moist decaying material, pet accidents |
| Blow Flies | Carrion, feces, compost heaps |
| House Flies | Animal waste, garbage, any moist organic material |
Seasonal Changes in Fly Attractants
The attractants that bring in the most flies change based on seasonal conditions:
Winter
Flies overwinter in protected areas like attics, beneath insulation, and inside walls. Garbage odors and food residue attract them inside. Keeping a clean home limits infestations.
Spring
Warming temperatures draw flies outside to human and animal waste. Pet droppings, dirty diaper pails, outdoor trash bins, and manure piles see increasing activity through spring.
Summer
Ripening fruits, vegetables, and crops attract high numbers during summer. Yeasty smells from fermenting sugars in compost heaps, spilled juices, and alcohol also peak.
Fall
Flies become desperate for food as temperatures drop in fall. Decaying leaves, overripe garden produce, and harvested grain residues produce strong attractant odors. Flies also seek shelter.
| Season | Top Attractants |
|---|---|
| Winter | Food residue, garbage odors inside homes |
| Spring | Warming waste from pets, diaper pails, garbage |
| Summer | Ripening fruits and vegetables, fermenting sugars |
| Fall | Decaying organic matter, overripe produce, shelter |
Preventing Flies through Sanitation and Exclusion
The best ways to prevent fly problems are:
Prompt Waste Removal
Frequently empty trash cans, recycling bins, compost piles, and waste containers to eliminate odors. Use sealed bags and take garbage to outdoor receptacles often.
Clean Up Spills Quickly
Don’t allow sugary spills, grease drippings, pet messes, or food debris to linger. Clean all areas thoroughly to remove fatty acids and potential breeding sites.
Install Physical Barriers
Use window and door screens, air curtains, and plastic strips in doorways to keep flies outdoors. Make sure screens are intact with no gaps or holes.
Keep Items Sealed or Covered
Store waste in lidded cans. Keep food covered. Use drain plugs when not in use. Eliminate access to potential breeding spots by sealing openings.
Fix Structural Issues
Seal cracks, holes, and crevices that allow fly entry. Repair damaged screens. Caulk and seal openings around windows, doors, pipes, and wires permanently.
Proper sanitation and exclusion tactics make areas far less attractive to flies. An integrated pest management plan should also include trapping and populations monitoring to handle any remaining pests. With diligence, fly problems can be prevented and controlled.
Conclusion
Flies are drawn to locations by various strong attractants including certain odors, visual cues, and optimal breeding environments. Decaying organic matter, fermenting sugars, ammonia, moisture, and warm temperatures bring in flies looking for feeding and nesting sites. Specific types of flies also target different materials such as fruit, feces, and garbage. Seasonal factors influence what attracts flies at different times of year. Preventing fly issues relies heavily on sanitation and exclusion tactics to remove attractants and deny entry. Understanding what attracts flies most can help focus control plans on the right areas to stop infestations.