Did you know the acid in your stomach is strong enough to dissolve razorblades?
And human hair is practically indestructible unless you burn it? (I've set my hair on fire twice...yikes!) No wonder it clogs our pipes.
By the way it is ok to tickle someone as long as their mouth isn't duct taped shut:) In other words as long as you don't tickle them until they stop breathing it is ok.