Glowing scorpion
Glowing scorpion by nate bolt, licensed under CC BY-SA 2.0

Everybody knows what a scorpion looks like and we all know you better stay well away from them. It’s not their pincers which are the dangerous part, but the stinger. And a rule of thumb with scorpions is: the smaller the pincers, the more venomous the scorpion.

So, you better stay away from them. Over day, this shouldn’t be to big of a problem since scorpions are nocturnal animals. In other words, they  only come out after sunset. After sunset is when they start to hunt their prey.

But how can we avoid them at night if we can’t see them? Well, this is where an amazing feature of the scorpion’s outer shell comes into play. A scorpion glows bright blue-green when exposed to UV-light. If you shine a UV-light on a scorpion, it will fluoresce. I know what you’re thinking, not everybody caries a UV-light with him during nighttime. But let’s pretend we do.

Why do they glow?

But why does a scorpion glow bright blue-green when exposed to UV-light? Before we answer that, you need to know that a scorpion does have enemies. Some type of rodents love a scorpion as a quick snack. When attacking the scorpion, they go for the venomous tale first. They bite of the stinger and from then onward the scorpion is as good as defenseless. But in order to attack a scorpion, they first need to find him. Their best chance is just after sunset, of during a moonlit night.

Glowing Scorpion Front
Scorpion Claws by Amanda, licensed under CC BY-NC-ND 2.0

The eyes of a scorpion cannot detect the UV light emitted from the moon, or just after sunset. They have no idea if the night is bright enough for their enemies to see them. However, the color their eyes can detect very well is green. So, if the scorpion can see his own body glow, this means it’s not dark enough and he should seek shelter.

So, there you have it. The blue-green glow a scorpion emits is part of a defense mechanism. It lets them know whether it’s safe to come out at night, or if they need to seek shelter and hide. Nature has some ingenious ways of helping a species survive, but this has to be one of the most creative.