Finally, someone has found the answer to one of life's nagging questions: Why is all this stuff in my belly button?
George Steinhauser reports that there’s a certain type of body hair that directs lint to the navel. His conclusions are published in the journal Medical Hypotheses under the title, "The Nature of Navel Fluff."
Steinhauser found that hairs around the belly button are scaly, WBBM reported. The hairs pull fibers from a person’s clothing and then pull them into the belly button.
The article notes: "Accordingly, and to the author's personal experience, navel lint seems to be a phenomenon that affects primarily male adults."
WBBM speculates that it's because women generally do not have hairy bellies? Or, perhaps more likely, it's because women keep their belly buttons clean.