Scorpion
Glows blue green under ultraviolet light, for reasons nobody has settled. The emperor is the one most people keep, and it spends the day under something.
Photo by Kevin Walsh from Oxford, England, CC BY 2.0
Overview
The emperor scorpion is the one nearly everybody starts with, and it is a far calmer animal than its reputation. It averages 20 centimetres, which makes it one of the largest scorpions in the world, and it comes from the forests of west Africa, where it lives under leaf litter and fallen wood and inside termite mounds.
The venom is mild and mainly defensive, and the sting gets compared to a bee's. A grown emperor rarely bothers with it for food anyway, because it kills with its pincers instead. It lives 5 to 8 years in captivity, gives birth to 10 to 12 live young after a gestation of about nine months, and takes four years to reach maturity.
Temperament
Nocturnal, timid, and usually under something. An emperor spends the day in a burrow or beneath a piece of bark, and the visible part of keeping one is the hour after the lights go off.
It is also one of the few scorpions that tolerates company. They have been recorded living in colonies of up to 15, and small groups work in captivity when the enclosure is big enough and everybody is well fed. The blue green glow under ultraviolet light is real and it is the cuticle itself doing it, not a trick of the bulb. Nobody has settled why it happens.
Care and grooming
Two or three adult crickets a week for a full grown emperor, plus a shallow water dish it can climb back out of. Uneaten prey comes out, same as with anything else that moults.
The safest way to move one is long, foam tipped forceps or herding it into a container, and that is not really about the sting. It is that a dropped scorpion is an injured scorpion, and they are more fragile than they look.
Living and exercise
Floor space, not height. Around ten gallons for an adult, wider than it is tall, with a hide big enough for the whole animal to disappear under.
Six or seven centimetres of damp peat free substrate for a forest species like the emperor, and a heat mat covering about a third of the base rather than all of it, holding roughly 25 degrees C at the warm end. The gradient is the point: the animal chooses its own temperature, and it cannot choose if the whole floor is the same.
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