Scorpions are neither insects nor spiders; they are distant cousins of the spider and are animals in the Scorpiones order, beneath the class Arachnida. Unlike insects that have six legs, scorpions and spiders both have eight legs, and scorpions have only two body segments, compared to the insects' three.
Like insects and other arthropods, scorpions have an exoskeleton; others in its class with exoskeletons include spiders, ticks, centipedes, mites, crustaceans and millipedes. These creatures all grow through the process of molting, which involves shedding the skin, and they all have jointed appendages. Unlike insects, scorpions do not develop wings, nor do they possess antennae.