Fluorescent chemicals in the exoskeleton of a scorpion absorb ultraviolet light and reflect it back as a glowing cyan-green hue, a process known as cuticle fluorescence.

A closer look

Fluorescent chemicals in the exoskeleton of a scorpion absorb ultraviolet light and reflect it back as a glowing cyan-green hue, a process known as cuticle fluorescence. Scientists still do not fully understand why this happens, though theories suggest it helps them measure moonlight or simply acts as a biological sunscreen against harsh desert rays. This means that if you walk into a dark desert with a blacklight, the ground will light up with glowing, venomous predators like some sort of terrifying, arachnid-themed rave. It is completely unnecessary for one of the most frightening creatures on earth to also possess the ability to glow in the dark like a cheap novelty toy. At least they have the basic decency to illuminate themselves so you can accurately see your impending doom before they sting your ankle