Scorpions keep themselves well hidden during the daylight hours, but at night they leave their lairs to hunt small ground-dwelling arthropods. Late in the summer they are very active and can be found quite easily. When exposed to ultraviolet light (we use a hand-held flashlight type), proteins in the scorpion’s exoskeletons glow a vibrant blue-green, lighting them up like beacons against the night!
We consider scorpions as beneficial to the GNG, as they keep the populations of many arthropods in check. Anyone who encounters one in his or her garden is encouraged to try the path of coexistence instead of extermination. Of all the scorpion species found in the Greater Los Angeles area, none are considered dangerous or aggressive. But because it is true that they can inflict a painful sting, it’s best to give them their space.
Silvestri’s Scorpion – Paruroctonus silvestrii 
In this clip of a GNG’s Silvestri’s Scorpion, you can see the visual transformation between illumination with white light and ultraviolet light.