It turns out it might be because they’re following orders—specifically, the photographer’s. When Olympic winners pose for a victory image, a sea of photojournalists are snapping away and asking athletes to do something besides just stand there and smile. With no other props handy, winners have picked up the habit of nibbling on their medal to satisfy the photographic feeding frenzy.

If you’re wondering whether anyone has chipped a tooth doing this, the answer is: of course. In 2010, German luger David Moeller broke off the corner of his tooth chomping on his silver medal. (Good thing his mother is a dentist.)

Of course, biting on gold used to be a way to tell if it was genuine (the real thing will show slight bite marks). But most Olympians probably know by now that their gold medal is mostly made up of silver and copper. If they were actually solid gold, the prizes would cost the IOC about $17 million.

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