Frequently Asked Questions about Scorpions.

The purpose of this page is to present answers to some of the questions I often get about scorpions. This page will gradually be extended as more questions occur. This page is devoted to questions about scorpion biology only, and will not adress questions about captive care of scorpions and scorpions as pets.

What is what on the scorpion body?
Click here for a short introduction to scorpion anatomy. A big thanks to Daniel Hill for allowing me to use this picture!

What is a scorpion?
Scorpions are members of the class arachnida, which also includes spiders (Aranea), mites (Acari), harvestmen (Opiliones), camelspiders (Solifugae), whip scorpions (Uropygi), whip spiders (Amblypygi), Peudoscorpions (Pseudoscorpiones) and a few more smaller orders. Scorpions are easy recognizable by their characteristic pincers and the tail with a stinger. Another uniqe characteristics for scorpions is the comb-like structure on the underside known as pectines.

Where can I find scorpions?
Scorpions are distributed in tropical and some temperate areas on all continents except Antarctica and New Zealand. In Europe, northern distributied is south of the Alps (but an introduced population of Euscorpius flavicaudis exists in southern England). In North America, scorpions can be found as north as southwestern Canada. Scorpions are occationally found outside their natural areas, but these are introductions resulting from scorpions traveling as stowaways in luggage, transports of merchandises etc.

Scorpions can be found in all kinds of habitats, ranging from dry deserts to rainforests, beaches to mountaintops, isolated, rural areas to utban populations in major cities living in cracks and crevices of the walls of houses.

Scorpions can be found in all types of habitat from dyr deserts to humid rainforests and on beaches near the sea to high up in mountains. The altitude record for scorpions is held by Orobothriurus huascaran from Peru. This scorpion was found at 4910 meters.

How do I find scorpions?
Most scorpions are nocturnal and will hide during the day. Some species will hide under stones and other suitable objects on the ground. Others will hide in cracks and crevices in rock, trees, houses etc. Some species prefer hiding under bark of old and dead trees. Finally, many species make own burrows in the substrate.

Scorpions can be found by turning stones and other objects that the scorpion will use to hide during the day. It is important to always look before you put your fingers any place. Also, always turn the stone against you (the opening away from you) in case there is an angry snake under the stone. Look under and inside old logs, under bark etc. Finding species hiding in cracks and crevices and in burrows during the day is very difficult. Scorpions can be found in the dark by using a flashlight with a UV bulb/LED (blacklight). This because scorpions fluorescence when illuminated with UV light (Picture). Scorpions can be seen from meters away as glowing, greenish ghosts in the dark, and easily caught by using a forceps. The best time will be 2-3 hours after dark, and with no moon. Using a UV flashlight is far the best way to find scorpions. The link section has a list of suppliers of UV-flashlights that can be used for scorpion hunting.

How large/how small can scorpions get?
Scorpions come in many sizes. The longest scorpion is probably Hadogenes troglodytes from southern Africa, which can reach more than 21 cm in length. Long scorpions are also found in the genera Heteromtrus, Pandinus and Heteroscorpion. The rumour about an Asian Heterometrus measuring up to 30 cm is probably only a myth, as it has never been verified by reliable sources. The heaviest scorpion is probably Pandinus imperatur, which can weight more than 50 gram (adult females). The smallest scorpions are found in the genus Microtityus, which only reach 12 mm in adult lenght. There are also other small genera, some of them recently described because of they cryptic way of life. Most scorpions are 4-12 cm long. A couple of fossil scorpions, e.g., Brontoscorpio, may have been as much as 1 meter in length.

How long have scorpions been on earth?
Scorpions are a very old animal group, turning up in the siluarian period (more than 400 million years go). They were around long before the dinosaurs. We know very little about these primitive scorpions, but it is possible that they lived in water (because they were not well adapted to land walking). Some of the fosils discovered measure more than a meter in length. Interestingly, the first scorpions were very similar to todays scorpions.

How long does scorpions live?
Scorpions are unusual long lived compared to other invertebrates. Most scorpions reach maturity in 1-3 years (some species take longer time), and live for 1-3 years as adults. This means that scorpions can live from 2-6 years, but there are few life span studies. Some species can undoubtly get older (like the slow growing Hadogenes. It is important to note that scorpion growth is dependent on several factors, like temperature, food access, reproduction (mated individuals tends to die younger than virgins), stress etc. Scorpions get older in captivity than in nature. Females live longer than males.

Are all scorpions venomous?
All scorpions have venom, but only a snall number can cause serious morbidity in humans. Most scorpions are only dangerous to their prey.

Is it true that the large scorpions are most dangerous?
No, this is not true. The largest scorpions of the world are usually quite harmless for humans and use their pincers as defense in stead for the stinger (and venom). Dangerous scorpions are usually less than 10 cm in length (with the exception of a couple of Parabuthus from Southern Africa, which grown more than 10 cm in length.

How can I tell if a scorpion is dangerous?
Firstly, you should never touch an unknown scorpion, and scorpions found in nature are best left alone. A general rule of thumb can be used to tell the dangerous scorpions from harmless species. Scorpions with large powerful claws are mostly harmless (important exception: Hemiscorpius lepturus), while species with thin, slender claws might be dangerous. Please note that a lot of species with slender claws are harmless too, but you need experience to separate the dangerous ones from the harmless. So it is best to regard species with slender claws as potential harmfull.

Jan Ove Rein (C) 2023