Dmitry Epov / Alamy Starting in 2005, Georg Steinhauser – then a chemist at the Vienna University of Technology – collected pieces of belly-button fluff from his navel and recorded their colour and weight. Over the next three years he collected 503 pieces of lint, weighing almost a gram in total. Eventually, he sent some of his lint off for chemical analysis, and published his findings in a scientific journal. And all in the interests of answering the question: why do some people find so much fuzz in their belly buttons? The answer, it appears, depends on your clothing and how hairy your navel is.