The vinegaroon, or whipscorpion, is found in the desert environments of much of the southern U.S.  Utilizing rock or logs to hide under during the heat of the day, it prefers to hunt at night.  Their primary target is the insect population that also inhabits these areas.  The vinegaroon has a unique defense.  When a potential enemy gets too close, it is able to secrete a fluid from the base of the "whip" that smells strongly like vinegar.  The pincers used to hold and grind food are actually modified mouthparts. (from butterfly.org)