Scorpion

Scorpions are arachnids, relatives of spiders, and they have a surprising secret: they glow blue-green under ultraviolet light. They hunt at night, gripping prey with their pincers and using the stinger only when needed. Compare the large, calm emperor scorpion, a popular pet, with the highly venomous deathstalker scorpion and the desert hairy scorpion, the largest scorpion in North America.