My friend Mallory, a project manager for a digital agency in Nashville, used some creative strategies to carry tampons at her old job. Her office was situated at the end of a long hallway, meaning she had to walk past everyone else to get to the bathroom.

“I would make sure I took care of things in the morning and then always have to remember to take my purse with me to lunch,” she says. “And then one day I was in a bind, I had already gotten up to get coffee and then get water and then I came back to my desk and I realized I hadn’t changed my tampon. It feels too awkward to get up from my desk in the middle of the day and walk out with my purse and then walk back in five minutes later. Then I look at my coffee mug, it was empty. So I stuck a tampon in an empty travel coffee mug and walked to the bathroom. And that was my plan.”

Nadine Ajaka / The Atlantic

Mallory also mentioned a friend of hers with an even sneakier approach—this person apparently hides tampons in the bathroom stalls at her office in the morning, and just hopes they’re still there when she returns.

Why go to all that trouble?

Secrecy is a key element of the modern period—the existence of tampons and pads in the first place allows women to “pass as non-bleeders,” as Sharra Vostral puts it in her book Under Wraps: A History of Menstrual Hygiene Technology. Barring any mishaps, the blood is only visible behind closed doors. Women’s public bathrooms have special trashcans in the stalls so feminine products can be disposed of neatly and privately.

Some of this, surely, comes from the disgust associated with all bodily fluids, and a preference to keep dirty-but-necessary animalistic activities (like excretion) cordoned off by bathroom walls, out of the public eye. But if excretion is a great equalizer (Everybody Poops, as the children’s book says), menstruation divides. Only half the population is biologically predisposed to do it, and the other half would largely prefer not to know about it, thank you very much. Many religions have historically dubbed menstruating women “unclean” and secular shame abounds as well, with jokes aplenty about “that time of the month” and teen magazine “Most Embarrassing Moments” columns filled with period-related anecdotes.

“Menstrual etiquette requires that women hide the fact of their periods…from others, especially from men. Accordingly, they take great pains to keep hygiene products out of sight,” writes Rebecca Ginsburg in her 1996 study “‘Don’t Tell, Dear’: The Material Culture of Tampons and Napkins.”

Pads and tampons themselves often seem designed to be hidden—for one, there’s the plethora of smaller, more “discreet” designs like Tampax Compak and U by Kotex Click, and a couple years ago Tampax introduced its “Radiant” tampons, which boasted a “softer, quieter wrapper.”