Everybody's doing it. Picking their nose and chewing it. Some people think it's funny but it's snot.
In this video from the Institute of Human Anatomy, "lead dissector" Jonathan Bennion explains why picking your nose can be dangerous.
"The fact is, picking your nose is part of what it means to be human," Bennion says, "but with that said, if you're two knuckles deep looking for buried treasure, that's definitely not a good way to go about it and your nasal anatomy would agree."
So in summary, you can pick your nose. And you can pick your friends. But you can't pick your friend's nose. And you probably shouldn't pick yours either.