The Lizard, I'm sure that is because they can just feel the vibrations from further down into the ground.. Or.. something..

A defence mechanism against predators..At least that's what I would think..
As for a
sixth sense.. well.. that's nothing special, we have far more than six senses... it's around twenty or so..
Example, our sense of heat.. We can tell that one thing is hotter or cooler than another..
If we close our eyes and hold out a hand.. we can always find that held out hand with our other hand.. straight away.