Enjoying the outdoors is a favorite pastime until a swarm of uninvited guests shows up: FLIES. Bug sprays and insect repellents such as DEET are proven and effective fly repellents, but in recent years, people have looked for natural fly repellents that actually work.
So, which natural fly repellents are scientifically proven to keep flies at bay? We’ve researched which have scientific backing versus which have mostly anecdotal support.
In this article:
- How To Make Natural Fly Repellents
- Historical Uses of Plants as Fly Repellents
- Natural Fly Repellent Ingredients that Work
- Keep a Tidy Lawn to Reduce Flies
- Some Natural Solutions Attract Flies
- Unregistered Repellents
- Are Plant-Based Products Better?
- Don’t Forget the Fly Swatter
- FAQ About Natural Fly Repellents That Actually Work
How To Make Natural Fly Repellents
DIY fly repellent spray: In a bowl, mix 1 cup of water, 1 tablespoon of vinegar, and a few drops of dish soap. Spray around the home to deter flies. You can use the following essential oils to boost the power of the spray, but always use caution with essential oils. They can cause allergic reactions and harm pets.
Most effective essential oils: Lemongrass, catnip, citronella, and cinnamon
Toxic to pets: Lemongrass, cinnamon, tea tree, and peppermint essential oils, among others, should be avoided around cats and dogs.
DIY fly killer spray: Mix ½ cup of water with ½ cup of isopropyl alcohol (found at your local drug store) and 1 teaspoon of liquid dish soap into a spray bottle (add water first so soap doesn’t bubble). Spray directly onto pesky flies to kill them.
Historical Uses of Plants as Fly Repellents
It’s unquestioned that at least some plants have insect repellent qualities. It stands to reason: Plants don’t want insects gnawing on them any more than we do. So as they evolved, plants developed natural bug repellent properties.
Many plants release a vapor when eaten, for example. Ancient people didn’t know that, but they did know burning the leaves of some plants, such as the neem tree, would lessen the bother.
Some are more effective than others, but data is still being collected on the topic.
Natural Fly Repellent Ingredients that Work
Here’s a breakdown of some scientifically proven solutions for your spray bottle, along with a sample of common folklore solutions, supported mainly through anecdotes.
Ingredients With at Least Some Scientific Backing
- Oil of lemon eucalyptus (OLE): According to the Centers for Disease Control (CDC), EPA-registered products with the active ingredient OLE (or PMD, its synthetic counterpart) “provide repellent activity sufficient to…reduce the bites of disease-carrying insects.”
Pro Tip: It’s important not to confuse “oil of lemon eucalyptus” with the similarly named “lemon eucalyptus essential oil.”
- Lemongrass oil: According to a 2013 study, “The Repellency of Lemongrass Oil Against Stable Flies…,” stable flies spent significantly more time in the study’s untreated zone than in the treated zone.
Pro Tip: Lemongrass essential oil is toxic to pets.
- Catnip: A 2009 study by the University of Nebraska-Lincoln found that catnip essential oil was quite effective as a natural repellent, with an average repellency rate of 96 percent against stable flies and 79 percent against houseflies.
Pro Tip: Growing catnip in your home or garden can help repel flies.
- Coconut oil: In a study by the USDA’s Agricultural Research Service and published in Scientific Reports in 2018, compounds derived from coconut oil proved to be a better repellent than DEET. When tested against stable flies, the coconut oil compound was more than 95 percent effective, while DEET was only 50 percent effective.
Pro Tip: This compound is specific to coconut fatty acids — not coconut oil itself.
- Citronella: According to a 2011 study on plant-based insect repellents published in Malaria Journal, “Citronella-based repellents only protect from host-seeking mosquitoes for about two hours, although the formulation of the repellent is very important.” Depending on other additives in the repellent, citronella can be more effective.
Citronella candles also are extremely popular, but “field studies against mixed populations of nuisance mosquitoes show reductions in biting around 50 percent, although they do not provide significant protection against mosquito bites,” the report said.
Pro Tip: While citronella essential oil products can be safe to apply to the skin, they are toxic to many pets.
- Cinnamon: Not only is it a fly repellent but a great DIY air freshener. Alone or combined with other methods, flies sure hate it.
Pro Tip: Cinnamon and cinnamon oil can cause skin irritation and digestive problems in pets and humans.
Mostly Anecdotal Support
- Witch hazel and apple cider vinegar: A popular home remedy, a mixture of witch hazel and apple cider vinegar along with a touch of eucalyptus oil will ward off flies because they don’t like the smell.
- Essential Oils: Lavender oil, tea tree oil, rosemary oil, peppermint oil, rose oil, and more.
While all have shown some promise with keeping bugs away, it’s best to use this in combo with other methods and enjoy the scent.
- Basil: Consider as a candidate for gardening indoors.
- Plastic bag of water: Flies have eyes consisting of thousands of little lenses, making them highly light-sensitive. That’s why having a bag full of water on your window or doorstep could reproduce a natural disco ball effect and thus repel some flies. Some suggest adding a penny to the bag to increase the effect.
- Hairspray hack: Chase and spray them, pesky intruders! Hairspray will cause wings to stick and bugs to fall on the ground. You know what to do from there on.
Keep a Tidy Lawn to Reduce Flies
Though natural fly repellents’ day has not yet fully arrived, there’s still plenty you can do to reduce the insect’s presence in your life. One of the best ways to keep flies away is to maintain a lawn and garden that flies find unattractive.
Here are a few ways to keep flies at bay in your lawn:
- If you have a composting pile, you’ll want to place it in a corner of the yard away from the house. Flies are attracted to decaying organic matter, so they will love your compost pile. If the pile includes fruit, it’s almost guaranteed to attract fruit flies.
- Grass clippings and leaf piles can serve as valuable nutrients for your lawn, but make sure they are spread evenly to promote quick breakdown or they will attract flies.
- There are a number of herbs and plants credited with keeping flies away, so you can add these to your garden or grow them in pots and move about as needed. These include:
- Basil, Mexican marigolds, mint, rosemary, lavender, yarrow, and pitcher plants
- Clean out all areas that collect water, as these attract not only flies but female mosquitoes, as well.
- Make sure animal waste is removed and disposed of properly as this, too, can create a fly problem.
- Trash cans should be well-maintained and closed at all times.
Some Natural Solutions Attract Flies
Instead of repelling flies, some repellent recipes attract them into a trap.
Sugar-Sweet Flytraps: Particularly good at catching gnats and fruit flies.
- Glass bottle or mason jar
- 2 tablespoons of apple cider vinegar
- 1 tablespoon of sugar
- 1 cup of water
- Dish soap (a couple of drops)
- Plastic wrap and a rubber band to secure it
- Mix ingredients together in a mason jar.
- Cover with plastic wrap (make certain it’s tight across the top).
- Secure with a rubber band.
- Poke a few holes in the top and place close to fruit or wherever these pests are congregating.
Soda-bottle traps: Great for house flies and a fun DIY project to do with the kids.
- Plastic soda or water bottle (any size )
- A sharp, serrated knife (please, be careful)
- Bait: The more attractive the bait, the more flies you’ll get. Soda or sugar water, honey, or old fruit works well
- Carefully draw a line with a marker and cut off the top of the bottle below where the neck tapers, usually just above the label works.
- Flip the top upside down without the lid and put it into the bottom like a funnel. Note: If the top is cut too small and falls in the trap won’t work.
- Bait: Water and something sweet. A 50/50 mix of sugar and water, fruit pieces, or even a few drops of fruit-scented dish soap works.
Pro Tip: You can hang the trap by punching two holes through both layers of the trap, then thread wire into holes, crimp ends of the wire, and voila! A hanging fly trap.
Flypaper: Modern versions are not toxic, they’re just sticky. Flypaper has dropped in popularity in recent years, probably due to having dead fly bodies suspended in living spaces. You can buy them at most grocery or hardware stores, or on Amazon.com.
Carnivorous Plants: Plants that trap flies, like the pitcher plant, will munch on the bugs and set you free.
Some plant-based fly deterrents (legally) fly under the regulatory radar. The Environmental Protection Agency (EPA), has listed several natural ingredients often used in these repellents as minimum-risk pesticides. Products with these active ingredients are not registered by the EPA.
Examples of ingredients used in unregistered repellents are:
- Citronella oil
- Cedar oil
- Geranium oil
- Peppermint and peppermint oil
- Soybean oil
Note: The EPA does not evaluate these ingredients for effectiveness, only whether they’re safe for people to use. Without science to prove how they repel flies and other insects, these natural fly repellent sprays are more a matter of personal anecdotes and folklore.
The EPA’s webpage gives more information about minimum risk pesticides if you’re interested.
The 2011 study on plant-based insect repellents in Malaria Journal notes that testing efforts to evaluate and develop safe and effective products are ongoing:
“Recently, commercial repellent products containing plant-based ingredients have gained increasing popularity among consumers…[T]hese [products] are commonly perceived as ‘safe’ in comparison to long-established synthetic repellents although this is sometimes a misconception.”
Much more standardized testing is needed, the study said, “to better evaluate repellent compounds and develop new products that offer high repellency as well as good consumer safety.”
Are Plant-Based Products Better?
Even if a plant-based substance shows promise, that doesn’t mean it will lead to a product friendly to humans and the planet. As the study in Malaria Journal points out, “Some natural repellents are safer than others, and it cannot be assumed that nature equates to safety.”
It’s not necessarily true that extracting repellents from plants is better for the earth, either, the study says. “While plant volatiles are naturally derived, distillation requires biomass energy, extraction commonly uses organic solvents that must be disposed of carefully, [and] growing the plants uses agrichemicals, such as fertilizers and pesticides (unless sourced from a sustainable and organic source).”
Don’t Forget the Fly Swatter
While there is a case to be made for natural fly deterrents, science has yet to prove that all-natural remedies are anywhere close to being as effective as a fly swatter. Many, though not all, natural solutions are unscientific, anecdotal remedies passed down from generation to generation or, in today’s Internet age, passed along on social media.
For the best results, stick to ingredients that have scientific backing. With a little bit of science, trial and error, and a few fly swatters, you’re sure to find a few natural fly repellents that work.
FAQ About Natural Fly Repellents That Actually Work
Is There a Natural Fly Repellent that Actually Works?
Catnip oil, oil of citronella, and oil of lemon eucalyptus (or PMD, its synthetic counterpart) are included as active ingredients in EPA-registered insect repellents. A comprehensive approach yields the best results, though. A combination of repellants, attractants, and a clean home and yard will provide the best fly control.
What Scent Repels Flies the Most?
The ingredients that best repel flies include oil of lemon eucalyptus, lemongrass, catnip, citronella, and cinnamon.
Essential oils can be toxic for pets and cause allergic reactions in people so use them with caution. If you believe your dog has ingested or come in contact with essential oils or liquid potpourri, call your veterinarian or the Pet Poison Helpline at (800) 213-6680.
How do you Keep Flies Away Permanently?
Keep it clean. Make sure animal waste is removed and disposed of properly as this, too, can create a fly problem. Trash cans should be well-maintained and closed at all times. You should also clean out all areas that collect water, as these attract not only flies but also mosquitoes.
When to Call a Professional
Flies multiply quickly, and even clean homes can run afoul of these filthy creatures. If the DIY solutions don’t work or you need extra help, consider calling a pest control professional to find the source of why bugs are bugging you.
Main photo credit: Nixon Johnson / Pexels