Order of invertebrates in the class Arachnida. Commonly known as whip scorpions, they are superficially similar to scorpions but the first pair of legs is modified to serve as antennae-like sensory organs. They have a whip-like flagellum at the end of their abdomen but are not venomous and many species also have large scorpion-like pedipalps (pincers). Whip scorpions are carnivorous, nocturnal hunters.