Can hanging pennies in a bag of water really keep pests away? The natural pest control hack explained by experts

This bizarre pest control hack is thought to dissuade pesky flies through summer – but does it work?

An american front porch with white woodwork and decking, a black front door - why hang pennies in a bag of water
(Image credit: chuckcollier via Getty Images)

If you have ever been down to the southern states of America in summer, you may have noticed hanging bags full of water and shiny pennies – but why?

It turns out that the bizarre custom of hanging pennies in a bag of water is thought to be a great way to keep flies away outside, using light as a pesticide-free way to keep porches and yards free from pesky bugs. 

But does this unusual pest control hack actually work? We asked the experts for their thoughts – before you go hanging the contents of your wallet from your rafters. 

Why hang pennies in a bag of water?

The trick involves tossing a few pennies (or crumbled pieces of aluminum foil) into a ziplock bag filled with water and suspending the bag on your porch or wherever you're looking to keep flies away from,’ explains Rocky Beninato, founder and licensed exterminator at Quality Affordable Pest Control. It is thought to have originated in the southern states to help keep flies away from stewing iced tea in summer. 

If you have already tried other methods of keeping flies out of the house, such as citronella candles or screening a porch to physically keep flying bugs at bay, experts wouldn’t recommend turning to this old-wives tale as a backup – it could even be classed as a bug pest control mistake

white back porch with patio furniture

(Image credit: Benjamin Moore)

‘I don't recommend relying on this method of keeping insects at bay,’ says Nicole Carpenter, the president at Black Pest Prevention. ‘This method might work by refracting light through the water and bouncing off the shiny pennies, creating visual patterns that might confuse some insects, however, while the refracted light can indeed distract insects, this method can hardly significantly reduce the number of insects around you,’ she warns, ‘This is because not all insects are affected by light patterns, and many will quickly adapt or ignore the reflections.

‘There are other environmentally friendly methods, whose effectiveness has been proven.’ 

Brett Bennett, Director of Operations, PURCOR Pest Solutions, agrees: ‘This is one of those pest control hacks that people will swear by, but there's not any really conclusive evidence that it works outside of anecdotes. When I've used it in the past, it seems to work here and there, but I personally find the flash of light off the pennies and water to be pretty distracting and inconvenient especially when I'm out doing yard work or gardening.’  

Other natural ways to keep flies away

Luckily, there are several other more effective natural methods for dissuading flies, the experts continue.  

1. Use scent

citronella candle

(Image credit: faithie / Alamy Stock Photo)

Picking strong-smelling citrus scents, from candles or plants for pest control, will prevent flying insects from easily locating food, making it less likely that they will come and bother you, explains pest control expert Nicole Carpenter. Peppermint and lavender can have similar effects if you are not a fan of citrus yourself. 

Using scent is also effective to keep flies away from your body and to get rid of mosquitos, she continues. ‘Pesky insects such as mosquitoes, flies, and gnats locate humans by detecting CO2 from exhalation and sweat. By masking the scent of human exhalation and sweat with stronger scents, we can keep insects at bay. ‘  

Mainstays 14 oz Citronella Candle | $6.24 at Walmart

Mainstays 14 oz Citronella Candle | $6.24 at Walmart
Designed for outdoor use, this citronella candle is the best way to keep flies away while enjoying time outsidee. 

2. Use a fly spray

An amber glass spray bottle with block top

(Image credit: Future)

A natural homemade bug spray, such as a garlic, vinegar or tomato leaf spray can be more effective when dealing with a lot of flies in one area, continues pest control expert Rocky Beninato. He argues that this is the best method with more concrete proven results – especially for inside a house.  

3. Use air to your advantage

A close up of a metal fan next to some plants

(Image credit: Getty Images)

Flies require good wind conditions in order to fly without being tired out. If you have the resources, it can help to control the air around you using fans to keep flies from invading your space, says Nicole Carpenter, pest expert. 

‘Since windy environments are what many insects, including mosquitoes and flies, try to avoid, using a fan to create airflow can help you keep insects at bay.’ You can either direct airflow towards an open window to keep flies out (and push hot hair out at the same time) or use a fan to keep cool when sitting outside, pushing bugs away from you. 


What is the best homemade fly repellent?  

When making your own homemade fly repellent, combine a mixture of a few drops of dish soap, one cup of water, and a teaspoon each of baking soda and vinegar in a spray bottle. Shake this up and spray around areas infested with flies. The strong smell will scare them away, while the dish soap will make it difficult for them to land or walk around on coated surfaces.  

What kills flies on contact?  

When trying to kill flies naturally, pest experts recommend using a high percentage of isopropyl alcohol or rubbing alcohol in a spray bottle. Spray the flies directly, wait for a few minutes for it to take effect, and then clean away  

Although this home remedy for getting rid of flies is not 100% proven, it is not harmful to give it a go in conjunction with other pest control measures such as scent and physical barriers as an extra precaution. Just be aware that it might not be the best solution on its own.  

Chiana Dickson
Content Editor

Chiana has been at Homes & Gardens for two years, having started her journey in interior journalism as part of the graduate program. She spends most of her time producing content for the Solved section of the website, helping readers get the most out of their homes through clever decluttering, cleaning, and tidying tips – many of which she tests and reviews herself in her home in Lancaster to ensure they will consistently deliver for her readers and dabbles in the latest design trends. She also has a first-class degree in Literature from Lancaster University.