Do Scorpions Glow in the Dark?

Did you know that scorpions can glow in the dark underneath a black light?

It’s true! Nearly all scorpions will glow a purple, blue, green, or white-ish color when exposed to an ultraviolet or black light in the dark. Below we’ll use one of our our scorpions as an example.

Do scorpions glow in the dark?
This Asian Forest Scorpion (Heterometrus longimanus) fluoresces a purplish white color.

Juvenile and freshly-molted scorpions don’t glow in the dark however. This is because their exoskeletons have not yet had time to develop enough to produce the unknown substance that causes the glowing.

Heterometrus longimanus
Here is a photo of the same Asian Forest Scorpion pictured above without the blacklight.

Interestingly enough, scientists are not 100% sure what causes scorpions to glow or what the purpose or advantage the glowing gives to the scorpion. All that is known is that the substance is found in a very thin layer of the scorpion’s cuticle known as the hyaline layer and that as the exoskeleton hardens, the fluorescence is brighter.

It has been hypothesized that scorpions glow under blacklight for multiple reasons. Some believe it’s so that they can find other scorpions – scorpions have pretty poor eyesight plus they already blend in very well with their desert surroundings.

Others have said it’s to protect the scorpion from the sun – i.e. it’s a form of sunscreen. However, this doesn’t hold up as scorpions tend to come out at night. It’s even been suggested that the glowing is just a fluke of nature and actually serves no purpose at all.

Scorpion under blacklight
Here’s one of our scorpions under a blacklight.

The most recent research that has been done on the subject comes from California State University archeologist Carl Kloock. He believes that because scorpions dislike the light, they use the UV levels as a way to know whether or not they want to come out to hunt. Apparently, when there are more UV rays present, scorpions tend to stay in hiding and be less active than if it’s darker.

Backwater Reptiles has all kinds of scorpions for sale if you are interested in checking out this neat trait for yourself! We also sell blacklights specially designed for getting your pet scorpion to glow in the dark! Just use the drop-down menu on any of our scorpion pages to purchase one.