Quicksand: Mule & Donkey
Why is it that a mule won't sink in quicksand but a donkey will?
Well, first off, quicksand is pretty much only as dangerous as it is deep. It is a myth that there are tons of deep quicksand pits in the jungle. In fact, only a few deep enough to sink all the way into has ever been found. That being besides the point, I don't see a reason that one animal would sink and another not, nor have I ever heard that this is true. Nor could I find instances of this on the internet, so I don't know how this thought ever came about.