(WJW) — If you ever happen to find a dryer sheet inside your mailbox, it’s not a prank, there’s actually a pretty simple explanation for how it got there.

Turns out, some postal workers use a dryer sheet as a means to keep from getting stung by wasps while placing mail in residents’ mailboxes.

“I can’t tell you how many times, especially during this part of the year, where I’ve opened up a box to see a little nest with 3 to 5 yellowjackets just chillin,” one letter carrier, under the username istrx13, recently wrote in a Reddit thread. “If I’m really unlucky, they will have made their nest at the very back of the box so I wind up sticking my hand in not knowing they are there. We all know how temperamental these little insects are … Last year alone, I was stung 10 times on 10 separate occasions.”

The user noted that the dryer sheet trick should only be used as a preventative solution to wasps invading your mail box and that if the insects do set up shop, the nest needs to be removed immediately.

“So please, if you one day randomly see a dryer sheet at the back of your mailbox, just know that your carrier more than likely put it there to deter these Satanic creatures from building their home in it,” the user said.

According to the user, the scent from the dryer sheets is what causes the insects to stay away from mailboxes. It’s recommended to change the dryer sheet out once the smell has faded.

Anyone who believes they may have a wasp infestation should call in an expert for safe removal.