A dryer sheet tucked between the bills and the junk mail sounds like a prank. It isn’t, and tossing it in the trash could be a mistake.

Across the country, homeowners are opening their mailboxes to find a Bounce or Snuggle sheet sitting inside, left there deliberately by their letter carrier. 

The practice has quietly persisted for years, and it comes down to one thing, keeping wasps out.

Mailboxes make ideal real estate for stinging insects. They’re dark, sheltered from weather, and often go untouched for hours at a stretch, which is exactly what a paper wasp looks for when scouting a nesting spot.

Homeowners across the country have been finding dryer sheets tucked into their mailboxes, left there deliberately by letter carriers as a low-tech way to keep wasps out of dark, sheltered mailboxes that make ideal nesting spots. will milne – stock.adobe.com Entomologist Brandon Runyon of Swat Pest Management explains that pests seek out food, water, and shelter wherever they can find it. Bonita – stock.adobe.com

“Insects are always going to be looking for food, water, and harborage,” Brandon Runyon, an entomologist with Swat Pest Management told Realtor.com. 

He added that pests gravitate toward wherever those conditions exist, and mailboxes check every box. Runyon said he has personally discovered paper wasp nests inside his own mailbox.

The dryer sheet trick traces back to a 2010 study that tested Bounce’s “Outdoor Fresh Scent” sheets on fungus gnats, an experiment inspired by gardeners who claimed tucking a sheet in their pocket kept bugs away. Researchers found the sheets held up as a repellent, at least against gnats.

Dryer sheets contain linalool and beta citronella, compounds found naturally in lavender, mint, and rose geranium that create a floral scent bugs tend to avoid, though the research behind this, a 2010 study, tested the effect on fungus gnats rather than wasps specifically. oasisamuel – stock.adobe.com

Runyon said the science lines up with what’s inside the sheets. Dryer sheets are loaded with linalool and beta citronella, compounds that occur naturally in lavender, mint, and rose geranium, plants long known to keep insects at bay. 

Manufacturers use those same compounds to give laundry products, lotions, and candles their floral scent, pleasant to people, repellent to bugs.

Runyon was careful to note the fungus gnat study doesn’t prove sheets work on wasps specifically, since little formal research exists on that front. Still, postal workers keep swapping the tip on social media, and local news segments keep running it every summer.

Runyon cautions that the amount of those compounds in a typical sheet is likely too small to have much impact on most insects, and any effect wears off quickly. Shotmedia – stock.adobe.com

Scent may matter more than the sheet itself. A 2015 study found that Victoria’s Secret Bombshell perfume fended off mosquitoes for a full two hours after being sprayed on, while some fruity fragrances appear to draw insects in rather than push them away. One online commenter swore by Dove bar soap as a substitute.

But Runyon isn’t ready to crown the dryer sheet a real solution. He said the concentration of linalool and beta citronella in a typical sheet is too small to meaningfully affect most bugs, and whatever impact it does have will fade fast. 

He said a sheet stuffed into a crack where ants are entering a kitchen might scramble their scent trail temporarily, but the insects will eventually reroute or simply wait the smell out.

For longer-lasting results, he recommends planting lavender or mint near entry points, using sprays like DEET or picaridin (or cedar and lavender oil for a gentler option), setting traps matched to the specific pest, or simply keeping the mailbox lid closed so insects can’t get in at all. Pamela Au – stock.adobe.com

For anyone serious about keeping insects away, Runyon pointed to sturdier options. 

Planting lavender and mint near doorways, window boxes, or garden sheds provides a repellent that doesn’t wash out after one wash cycle. Sprays containing DEET or picaridin work fast, while cedar and lavender oil sprays offer a gentler alternative, provided shoppers match the product to the specific pest they’re battling. 

Traps, too, can help, so long as they’re designed for the right target, since ant traps, fly traps, and mosquito traps aren’t interchangeable.

As for the mailbox itself, Runyon’s advice is simple. Close the lid. No opening means no wasp can slip inside, and no unlucky letter carrier gets stung reaching in to drop off the mail.