Scorpions have the quality that they are fluorescent and glow when in contact with UV radiation. This becomes clearly visible, when they are directly exposed to UV light. However, the UV components, which are contained in the sunlight and the moonlight, are hardly sufficient to produce this glow to an extent that it is visible to humans. Still, scorpions appear to detect the UV components and hence react to moonlight.
Scientists disagree what the reason for the fluorescence might be. The attempts to explain reach from mating signals (does look quite impressive), to causing confusion for prey and even to the usage as an indicator of the amount of light, in order to determine an opportune moment for the nightly hunt. The latter appears to be more effective and successful with less moonlight. We already described this behavior with sharks and lions. It might also be possible that scorpions avoid the full moonlight because of not wanting to be an easy prey for larger predators. Most arachnologists (scientists of spiders and related animals), however, take the the view that the bluish and greenish glowing of the scorpions has no real use at all.
Scorpions do not belong to the most favorite animals of most people, yet they emanate a certain fascination that can be appreciated from an appropriate distance. No need for a close encounter.
Photo: Wikipedia, Fritz Geller-Grimm