Don't Put Your Finger in Your Nose... in your NOSE!

So as I sat here and watched a youngun' in my care today, pick his nose and quickly stick whatever it was he found up there, in his mouth... I threw up a little in my mouth... but after that a thought... sick as it is occurred to me, here is a kid that would not touch the lovely tostada I made him for lunch... saying "that is the food I don't like" to which I said "Too Bad", but he'll eat a booger... a booger, the stuff made of dust particles and our own mucus. HOW DISGUSTING.... but something compels kids and some really nasty adults... to eat them possibly every day. What compels them... is it some strange animal instinct... that I have long since ignored... is there some unknown benefit that we educated beings no longer understand. Or is it just the best hiding place for his booger he could find at the time??? Either way still makes the back of my throat lurch, and my stomach turn, and makes the words jump out "Don't, don't don't don't do that!"