The Curious Truth About Belly Button Fluff

• Belly button lint or fluff  is made of clothing fibres, hair and dead skin cells.
• The average man is home to 1.8 mg of belly button fluff at any one time, and it’s almost always blue. What is this mysterious substance, and why does it gather there?
• The navel is not just a home for unwanted bits of t-shirt. As an area with a large number of skin folds, not to mention a deep crevice, it is a trap for all sorts of dead skin, discarded fat molecules, bits of dust and assorted scales and proteins. Thus, that benign ball of fluff is in fact largely bits of you.
• Fluff may help make bellybuttons cleaner by collecting bacteria as it forms
• Dr Steinhauser hypothesized that the specialized fluff-catching hairs were in fact a deliberate attempt by the body at cleaning itself. Rather than allow the dead skin and other human detritus to fester and become a feasting ground for bacteria, the body uses available cloth to create an enticing object for human males to remove and flick away. 
• Fluff tends to take on the colour of the cotton fibres it's mostly made of
• Even if you shower every day, lint still collects.