Where does belly-button fluff come from?
The nature of navel fluff
A chemist collected his own belly-button fluff for three years to figure out where it comes from.
Georg Steinhauser gathered 503 pieces of his own navel lint and analysed them. It is mostly fibres from clothing mixed with dust, sweat and dead skin.
The culprit is belly hair: it acts like a barbed hook, scraping fibres off your shirt and guiding them toward the navel. Shaving the belly stopped the fluff completely.
Your belly button is a tiny lint-harvesting machine.