Underwear hygiene is often overlooked, but one terrifying case from China has sparked renewed awareness. A Chinese medical blogger known as “Dr. Do from Xiehe” recently shared a shocking story he heard during a dinner with colleagues: a man began urinating live larvae and was in severe discomfort. Lab tests later confirmed that his urine contained numerous insects.
Doctors believe the likely cause was the man drying his underwear in an unsanitary environment—possibly near a toilet or in a damp, dirty bathroom—where insects laid eggs on the fabric. These eggs may have hatched and the larvae entered his urethra through the underwear.
Dr. Do emphasized that insects prefer to lay eggs in “resource-rich” environments—meaning dirty or moist places. While clean underwear isn’t an ideal place for bugs, leaving them to dry in unhygienic areas like bathrooms or near garbage can increase the chances of infestation. Flies and moth flies (also known as drain flies) are common culprits. These insects feed on feces and rotting organic matter, thrive in damp conditions, and can lay hundreds of eggs at once.
To prevent such horrifying incidents, Dr. Do strongly recommends changing underwear daily and replacing them every six months. “Some people think underwear doesn’t need much care because it’s worn inside, but that’s wrong,” he said. “Worn underwear can carry waste, secretions, and bacteria. If not cleaned properly, it becomes a breeding ground for germs.”
In short, always dry your underwear in clean, dry areas, and never underestimate the importance of proper hygiene—even for your most basic clothing.

