Homeowners across the country have been finding dryer sheets tucked into their mailboxes, a practice initiated by letter carriers as a deterrent against wasps. Mailboxes, with their dark and sheltered interiors, offer an attractive nesting location for paper wasps, according to entomologist Brandon Runyon of Swat Pest Management.
"Insects are always going to be looking for food, water, and harborage," Runyon told Realtor.com. Mailboxes fulfill these requirements, and he noted that he has personally found paper wasp nests inside his own mailbox.
The tactic is believed to stem from a 2010 study that examined Bounce dryer sheets' "Outdoor Fresh Scent" as a repellent against fungus gnats. Gardeners had previously suggested that carrying a dryer sheet could keep bugs away.
Dryer sheets contain compounds like linalool and beta-citronella, which are naturally found in plants such as lavender, mint, and rose geranium. These scents are known to repel insects, and manufacturers use them in various household products for their fragrance.
However, Runyon cautioned that formal research specifically on dryer sheets deterring wasps is limited, and the concentration of repellent compounds in a single sheet may be too low to have a significant effect on most insects. He also stated that any repellent effect is likely to be short-lived.
For more robust insect control, Runyon suggests planting repellent plants like lavender and mint near entry points, using EPA-approved repellents such as DEET or picaridin, or opting for gentler alternatives like cedar and lavender oil sprays. Traps designed for specific pests can also be effective. He also advised that simply keeping the mailbox lid closed can prevent insects from entering.