Flies are attracted to certain smells and aromas for a variety of reasons. Some smells replicate the scent of decaying organic matter where flies like to lay their eggs. Other smells contain chemical compounds that flies instinctively want to consume. By understanding what types of odors and fragrances appeal most to flies, you can better prevent flies from infesting areas where they are unwanted.
Smells that attract flies
There are certain smells and odors that are well known to attract flies. These include:
- Decaying organic matter – Rotting food, animal feces, and garbage all produce smells that attract flies. The smell indicates a food source for flies to lay eggs.
- Vinegar – Flies are attracted to acetic acid which is found in vinegar. Traps containing vinegar are commonly used to catch flies.
- Fruit – Ripening fruit gives off aromas that attract flies. Fruit flies in particular seek out the scent of fermenting fruit.
- Wine and beer – Fermenting beverages contain aromatic compounds that appeal to flies. Fruit flies especially target wine and beer.
- Sweet substances – Sugary foods and drinks have an appealing scent for flies. Things like syrup, juices, and soft drinks can bait flies.
- Meat and fish – Rotting meat and fish provide an ideal breeding ground for flies to lay eggs, making the smell highly attractive.
- Ammonia – The smell of ammonia, found in urine and animal waste, is a strong attractant for flies.
- Grease traps – The oily organic smell from grease traps attracts flies looking for fatty foods.
In addition to food sources, flies target smells that signal optimal breeding sites. The presence of larvae and eggs can attract other flies to lay their eggs. Pheromones released by flies are also attractants. Understanding which odors are most appealing to flies helps identify potential fly infestations.
Why flies are attracted to certain smells
There are several biological reasons why flies are attracted to particular smells and odors:
- Finding breeding sites – The smell of decay signals ideal breeding grounds for flies to lay eggs in rotting organic matter.
- Locating food – Aromas emitted from ripening fruit, meat, and waste signal food and nutrients for adult flies.
- Sugars and proteins – Flies instinctively seek out sugars for energy and proteins for reproduction, making sweet and meaty smells appealing.
- Fly pheromones – Chemical mating signals released by flies attract other flies looking to breed.
- Fatty acids – The fatty acids given off by oils and grease traps are attractive food sources for flies.
- Ammonia – Some flies identify ammonia as an indicator of protein foods that support egg production.
Flies have specialized sensory receptors that detect chemicals in the air to locate breeding and feeding sites. Fly antennae are optimized for picking up the specific smells they are instinctively programmed to seek out. The drive to find food, mates, and egg-laying locations makes flies respond to the associated smells of those sites.
Smells that attract different types of flies
While many smells attract multiple fly species, some odors are more targeted to certain types of flies:
- Decaying organic matter
- Ripening fruit
- Fermenting fruit juices
- Wine and beer
- Soft drinks
- Decaying meat
- Animal carcasses
- Wounds on animals or humans
- Sweet substances
- Rotting meat
Identifying the type of fly infestation, based on the smells they are attracted to, allows for targeted prevention and control measures customized for that fly species.
How the sense of smell works in flies
Flies have an excellent sense of smell that allows them to hone in on specific scents. Here is how a fly’s sense of smell functions:
- Olfactory receptors – Flies have olfactory receptors located on their antennae and palps that detect airborne chemical compounds.
- Odor molecules – When odorous molecules dissolve into the fly’s lymph fluid on its antennae, they bind to receptors.
- Nerve signals – The binding triggers nerve signals that are sent to the fly’s brain to identify the odor.
- Brain processing – The fly’s antennal lobe in its brain processes the scent signals and compares them to known attractive odors.
- Behavior response – Recognizing an attractive aroma causes the fly to immediately orient towards the odor source.
Flies can detect faint traces of odor over long distances. Specialized receptors allow them to identify and differentiate thousands of specific smell molecules. This highly advanced olfactory system enables flies to quickly hone in on smells signaling an optimal food or breeding source.
How to use scents to trap flies
Knowing which smells flies find irresistible allows you to use those scents to trap and eliminate flies. Here are tips for using fly-attracting odors to trap flies:
Make DIY vinegar traps
- Fill a cup or bowl with apple cider vinegar which has a strong smell attractive to flies.
- Add a drop of dish soap to break the vinegar’s surface tension so flies sink.
- Cover with plastic wrap and poke small holes so the smell escapes.
- Place traps wherever flies are a problem.
Buy scent-based traps and baits
- Traps containing fly pheromones lure flies looking to mate.
- Fruit fly traps use vinegar and fruit juices to target those pests.
- Fly strips coated with sweet-smelling bait grab flies when they land.
Keep garbage and waste contained
- Make sure garbage cans have tight fitting lids to seal in rotting odors.
- Don’t allow animal waste or manure to accumulate in open piles.
- Use an odor absorbing gel in garbage disposals and drains.
Promptly dispose of organic waste
- Empty garbage frequently so it can’t rot and produce smells.
- Clean up fallen fruit from trees and gardens right away.
- Don’t allow meat, fish, or pet food residue sitting out.
Taking advantage of flies’ attraction to certain scents allows you to proactively control fly infestations through odor-based traps and reducing smell sources flies target.
Scents that repel flies
In addition to using attractive scents as a lure, certain smells can also repel flies and prevent them from lingering. These include:
- The strong citrus smell from lemons, oranges, limes and grapefruit repel flies.
- Cut citrus fruit halves or use essential oils of lemon and orange.
- Mint-scented oils, extracts, and fresh mint repel flies.
- Grow mint plants to deter flies from gardens and patios.
- Like mint, basil’s strong herbal aroma drives flies away.
- Grow basil plants near doors and windows to discourage flies.
- The pungent smell of dried bay leaves repels flies.
- Scatter bay leaves on countertops, window sills, and anywhere flies land.
- The potent clove scent overwhelms flies’ odor receptors.
- Use clove oil or place containers of whole cloves as fly deterrents.
Using fly-repelling aromas is a chemical-free way to discourage flies from lingering and breeding indoors. The strong herbal and citrus scents overwhelm flies’ sense of smell to drive them away.
Preventing flies with odor control
To keep flies away by controlling odors, follow these tips:
- Take out garbage regularly before it starts smelling.
- Rinse recycling to remove residue that produces odors.
- Clean trash cans and dumpsters to eliminate lingering smells.
- Fix leaky drains and pipes that allow organic matter to accumulate.
- Clean grease traps often to avoid rancid oil smells.
- Use baking soda or vinegar to absorb fridge odors.
- Clean up pet waste in yards promptly.
- Empty compost bins frequently to avoid rotting smells.
- Clean chimneys and flues to reduce fireplace odors.
By actively controlling scents that attract flies, you remove the stimuli that draw flies into homes and buildings. Proper sanitation and odor prevention practices are key to keeping flies away.
Using fly attractant smells against them
While certain smells lure flies, you can use fly attractant odors against them by:
- Baiting traps with vinegar or rotting fruit.
- Lacing insecticide sprays with sugar.
- Putting out containers of fermenting beer or wine.
- Leaving small amounts of manure in fly traps.
- Spraying ammonia around the outside of traps.
Flies can’t resist following scents that promise an ideal food or breeding source. Lacing traps and baits with the smells flies love leads them right to products that kill and capture flies.
Most effective fly attractant smells
Research has shown that the following scents are most effective at attracting and trapping the largest numbers of flies:
- Acetic acid in vinegar is irresistible to fruit flies and house flies.
- Cider vinegar has an extra sweet smell that flies love.
- Mixing vinegar with wine, juices, or sugar increases effectiveness.
- The smell of rotting meat contains fatty acids that lure blowflies.
- Meat also signals a breeding site for egg-laying to flies.
- While less pleasant, rotting meat is a top fly attractant.
- The powerful scent of ammonia provides a strong signal to flies.
- It indicates both a food source and breeding site to flies.
- Ammonia is most attractive to house flies and bottle flies.
Combining multiple fly-enticing smells boosts the effectiveness even further. Create your own bait by mixing vinegar, fruit juice, sugar, ammonia, and pieces of rotting meat or fish.
Flies detect smells with a highly advanced olfactory system that allows them to pinpoint specific scents signaling prime food sources and breeding grounds. Decaying organic matter, grease, fruit, and meat give off aromas that flies instinctively recognize as attractive locations. Knowing which odors appeals to flies allows you to control them through targeted trapping, sanitation practices, and deploying fly repellent fragrances. Harnessing the powerful sense of smell against flies is key to preventing unwanted infestations.