Considered mysterious and dangerous by most people, the scorpion piques curiosity when considered as a domestic pet, especially when we are talking about the larger varieties like Hadogenes troglodytes.
Hadogenes troglodytes, commonly known as “Flat rock scorpions”, are incredibly easy to care for. They do not require any special substrate and do not possess potent venom. All of these qualities make them suitable scorpions for beginners.
Nevertheless, caring for this species, like any other, has its peculiarities. For example, despite their large size, these scorpions grow incredibly slowly and only reach sexual maturity at 8-10 years of age!
In this article, I have compiled all the information known about Flat rock scorpions, including their biology, habitat, behavior, diet, and care needs.
Quick Notes about Flat Rock Scorpions
| Name | Flat rock scorpion |
| Other Names |
The Rock Scorpion or the Long-tailed African Scorpion |
| Scientific Name | Hadogenes troglodytes |
| Type |
Terrestrial |
| Tank size (minimum) | 2 gallon (~8 liters) |
| Keeping | Easy-moderate |
| Breeding | Medium-difficult |
| Average size | 8.25 inches (21 cm) |
| Optimal Temperature | 77 – 90°F (25 – 32°C) |
| Water type | Freshwater bowl |
| Moisture | 40 – 60 % |
| Substrate | Any |
| Diet | Carnivore |
| Temperament | Semi-aggressive |
| Life span | up to 30 years |
| Color Form | Dark-reddish |
Etymology of Hadogenes troglodytes
The genus name “Hadogenes” does not have a widely recognized etymological origin. However, there are 2 theories.
- The genus name “Hadogenes” is derived from the ancient Greek “Hadros” meaning “Thick, stout or strong” and the suffix “-genos” which means “Birth or kind”. Refers to the stocky build and large size of these scorpions compared to others in the same family.
- This is my favorite interpretation. The word “Hadogenes” also has Greek significance, but it is related to Hades (the Greek god of the underworld) and can be translated as “born of Hades.”
The species name “Troglodytes” (τρωγλοδύτης) is composed of two Greek words: “τρώγλη” (trōglē), meaning “cave,” and “δύνω” (dynō), meaning “to enter” or “to go into.” Therefore, “troglodytēs” can be translated as “cave-dweller” or “one who goes in caves.”
So the full scientific name refers to a “strong or stout kind that lives in caves”.
The Rock Scorpion or the Long-tailed African Scorpion
Taxonomy of Flat Rock Scorpions
The Flat rock scorpions belong to the family Hormuridae within the order Scorpiones. Hadogenes is a genus of large African scorpions with 18 described species.
Their taxonomy is quite complex and subject to revisions as new research emerges.
According to the study, reference to the original species descriptions does not assist much in most cases as these descriptions are often very brief and of virtually no diagnostic value. To complicate the matter further, the taxonomic status of many species and subspecies currently accepted are suspect.
For example, it is supposed that Hadogenes troglodytes also have subspecies such as:
- Hadogenes troglodytes matoppoanus
- Hadogenes troglodytes letabensis
- Hadogenes troglodytes dentatus
- Hadogenes troglodytes crassicaudatus
- Hadogenes troglodytes troglodytes
Distribution of Flat Rock Scorpions
Hadogenes troglodytes is native to Africa. Their distribution includes several countries in the region, such as Botswana, Mozambique, Congo, South Africa, and Zimbabwe.
Habitat of Flat Rock Scorpions
Flat rock scorpions are adapted to arid and semi-arid environments and are strictly and exclusively associated with rocky or stony environments.
Hadogenes troglodytes inhabits narrow cracks, crevices, and spaces beneath exfoliations of weathered rocks. Their behavior and physiology are specialized for life in such habitats.
Description of Flat Rock Scorpions
The main characteristic of Hadogenes troglodytes is that the scorpions are very flat (almost like somebody has stomped on them).
Distinguishing characteristics of Flat rock scorpions include:
- Size. Hadogenes troglodytes are one of the longest scorpion species in the world. Males can reach up to 8.25 inches (21 cm) in length (from the carapace to the tip of the sting).
Note: Only a few species (such as Gigantometrus swammerdami or Pandinus imperator) are more bulky and a bit heavier. - Shape. These scorpions are extremely dorso-ventrally compressed. The body is very broad and flat, the metasoma is laterally compressed, long, and slender. The front part of the scorpion’s body is mostly straight or slightly curved with a small groove and is smoother and shinier in females but duller in males.
- Eyes. The central eye spots are larger than the side ones, and all the grooves are there.
- Claws. The pedipalpal segments are extremely robust. The front part of the upper arm is big, thick, and hard. Everything is bumpy except the top part of the “hand” in males, which has a few lines. The lower part of the pedipalps is bumpy on the underside.
- Legs: There are bumps on the leg joints of the 1st and 2nd The 1st leg is also bumpy, while the 2nd to 4th legs are not as bumpy. The underside of the 1st leg has two bumpy ridges. The bottom of the 2nd to 4th leg’s joints is bumpy, but there are no clear ridges. The 2nd segment of the 1st to 4th legs has three spines on the underside.
- Metasoma: It is very thin and skinny. The first part of the tail is higher than it is wide at the back. The sides of the tail are smooth in females but bumpy in males. The bumps on the second and third tail segments do not end with large, spiky bumps.
- Telson: The top of the tail is very straight.
- Color. The carapace often ranges from dark to dark red, the pedipalps are reddish-brown, the tergites are dark reddish-brown, and the sternites are yellowish-brown.
For a detailed description of the Flat rock scorpion and its distinguishing features from some other species, you can refer to this and that scientific papers.
Related article:
Lifespan of Flat Rock Scorpions
Hadogenes troglodytes holds the title of the longest-lived scorpions on Earth. These scorpions can live up to 30 years!
However, this extended lifespan is closely correlated with their relatively EXTREMELY slow growth. For instance, the scorpions that are 3-4 years old will be just a little over 1 inch (2.5 – 3 cm) in length.
Behavior of Flat Rock Scorpions
Temper. These scorpions are not an overly aggressive species. On the contrary, they will prefer to retreat from threats rather than stand their ground. They are mostly defensive, not aggressive, almost like Emperor scorpions.
Sociality. They are solitary. Flat rock scorpions are not communal animals. In most cases, they do not live together in groups and do not tolerate even their own species.
Although there can be exceptions to the rule, you need to remember their cannibalistic tendencies.
Activity. Flat rock scorpions seldom leave their rock shelters where they stay completely flat with their tail down sideways. They are not true burrowers.
Interesting fact: In the wild, to avoid predation, they use their big and thick claws to close off the crack in front of the scorpion.
They are pretty shy and skittish.
In addition, they have poor eyesight and are of nocturnal habit. They are primarily active at night and spend the day hidden.
They don’t move around a lot, however, alerted scorpions can move at great speed and are difficult to pull off the rock without damage.
Features:
- Communal: No
- Activity: Low
- Peaceful: Semi-aggressive
- Burrowers: No
- Venomous: Yes
Venom of Flat Rock Scorpions
Their sting is described as mild burning pain lasting several hours.
Note: These scorpions do not sting readily or have large venom yields compared to more dangerous species.
While painful, the venom is not considered deadly to healthy adults. No human fatalities have been definitively attributed to the Flat rock scorpion. However, it could potentially be dangerous to small children, the elderly, or those with allergies.
According to the study, the venom from Hadogenes troglodytes is mildly toxic even to mice, having an LD50 value between 1800 and 2667 mg/kg.
Diet of Flat Rock Scorpions
The Flat rock scorpion is an opportunistic predator that feeds on various small prey in its habitat such as insects, centipedes, arachnids, small rodents, and even other scorpions. Scorpions are strictly carnivorous.
Scorpions primarily detect their prey through vibrations sensed by specialized organs. They have fine sensory hairs on their pedipalps, which can detect airborne vibrations, and small sensory organs at the tips of their legs that pick up ground vibrations.
They are more of a pincher scorpion. The prey is usually captured with powerful pincers instead of being intoxicated.
In captivity they can be fed a diet of:
- crickets,
- locusts,
- grasshoppers,
- mealworms,
- cockroaches,
- red runner roaches,
- worms, etc.
How Often to Feed Flat Rock Scorpions?
Generally, adults can eat once a week or two. Juveniles and females (after getting their young) will require more food (2 – 3 times per week).
| It is important to note that these scorpions have one of the lowest metabolic rates ever recorded, with some scorpions having survived, in good health, without food for over a year.
Therefore, do not panic, if your scorpions do not eat. Just try again in a week. When they get hungry, they start sitting at the entrance of their hide. |
Some Feeding Tips
- Time. Flat rock scorpions are Therefore, it is highly recommended to feed them at night (at least in the evening). By doing so, you will replicate the conditions and environment under which they eat naturally.
- Prey size. It is absolutely important that prey be smaller than the scorpions to ensure that they can grab it easily with their claws. Ideally, their food should not be larger than their stomach.
- Prey activity. Flat rock scorpions are not active hunters. So, do not give them prey that will burrow, jump, or fly around their enclosure. For example, remove the wings, chop the forelimbs, break the legs, or squash the head so that they wiggle and are easily accessible to the scorpions.
- Refuses to eat. Do not leave the live food in the enclosure. If your scorpion does not want to eat you need to remove it the next day.
- Check the hiding spots. Keep in mind that scorpions often drag and store food in their hiding spots for later consumption. Check them from time to time to prevent any mold, mites, or bacterial contaminations. If it is not eaten in 2 days, remove it.
| Important: All these tips can, in some cases, even save your scorpion’s life!
There have been numerous cases where large live prey or prey that could actively fight back (such as crickets) killed scorpions. Even more, there have even been cases where seemingly harmless mealworms killed scorpions when they started molting. So always make sure their food doesn’t bury itself or have the ability to actively escape. |
Related article:
Keeping and Housing Flat Rock Scorpions
Enclosure Type:
To begin with, selecting an enclosure that can maintain adequate levels of heat and humidity is crucial for housing scorpions. There are 3 main choices available to achieve this.
First of all, you will need to choose an enclosure that provides the appropriate levels of heat and humidity for these scorpions. There are several options here.
1. Plastic container (Recommended)
| PROS | CONS |
| Cheap. | Plastic is not the most ecological material, especially in hot temperatures. |
| Good for ventilation. | Not aesthetically pleasing |
Note: Even if there are no holes in the container, we can easily do those ourselves. Drill a few small holes on two opposite sides of the walls (closer to the base and closer to the upper edge).
2. Terrarium (Second best option)
| PROS | CONS |
| It is made of ecological materials. | Some models have problems with ventilation |
| Looks very nice | High cost and weight |
3. Aquarium (so-so)
| PROS | CONS |
| It is made of ecological material (glass) | There can be problems with the ventilation |
| Very easy to buy | Fragile |
| Expensive | |
| Heavy |
Related article:
Tank size:
The minimum size of the enclosure for Flat rock scorpions should correspond to the length of the scorpion’s body. Here are the recommended minimum dimensions:
- Length of the enclosure = twice the length of the scorpion’s body.
- Width of the enclosure = one and a half times the length of the scorpion’s body.
- Height of the enclosure = the same as the length of the scorpion’s body.
In a larger tank, it can be easier to make diverse areas for them to hide.
The only problem that may arise with a larger enclosure is that during feeding, their prey can run and hide from the scorpions for quite some time, given that scorpions are not active hunters.
| IMPORTANT: Make sure that the tank has a secure lid to prevent the scorpions from escaping! |
Light:
No special requirements. Ambient light will be enough. Flat rock scorpions are nocturnal animals.
Note: Although the physiologic importance of light is not well understood for scorpion species, but the significance of a light cycle for invertebrates in general has been determined.
UV lightingFlat rock scorpions glow under black light. This can attract and excite anybody in your family. Blacklight is also an option to make the environment safe in the house while there is a scorpion living. It can help in locating the scorpion if it escapes its cage. However, UV lighting is not completely safe for scorpions. It stresses them. The point is that ultraviolet is simply a normal part of the light from the sun. These scorpions do not like to be exposed to the sun. Related article: |
Temperature:
Flat rock scorpions prefer a warm temperature range of 77 – 90°F (25 – 32°C).
To keep a temperature steady, heat sources like heat lamps or heating pads can be used.
Tips:
- Keep the heat lamp only on one side, not the middle.
- The best (safest) option will be to put the heater to the side of the tank. If you use an under-the-tank heater, it can overheat your substrate and burn or kill molting scorpions there.
Humidity:
Flat rock scorpions need a level of humidity between 40 and 60%.
High humidity may cause fungal infections (mycosis – black patches). This is also one of the main reasons why people fail to keep desert scorpions in captivity.
Related article:
Water:
Although Flat rock scorpions get most of their water from their food, it will be better to give them access to water through a dish anyway.
Even a small plastic bottle cap will be enough. Fill it 1-2 times a month and let it evaporate dry.
Note: Water dish does not cause mycosis, only high humidity does.
Interesting fact: Scorpions have extra layers of lipids (fats) on their exoskeleton that minimize water loss.
Substrate:
Flat rock scorpions may push aside some substrate but in reality, they do not make deep burrows. Therefore, it is possible to use almost any dry substrate. Sand is, probably, the simplest choice.
Hiding places:
In their enclosure, make sure to provide plenty of dark hiding spots using rocks, stones, and other decorations to enrich their environment.
| Important: Creating proper hiding spots is crucial in this regard. Simply piling up rocks won’t be suitable for Flat rock scorpions. For their comfort, the gaps between the rocks should be very narrow. Thus flat rocks will be an ideal choice. Just be careful so they won’t collapse (some people even use glue or silicone for that). |
Handling Flat Rock Scorpions
These scorpions have relatively weak venom and are typically not considered aggressive. However, they are wild animals. Flat rock scorpions are not pets you can play with!
It’s also crucial to ensure that children do not provoke the scorpions since it’s unethical, and such actions have consequences.
It’s not advisable to take them out just because you want to. The scorpions do not benefit from being handled, and they easily get stressed. Therefore, it’s best to handle them as little as possible.
However, if you must take them out, it’s preferable to use rubber gloves and follow these steps:
- Put your hand slowly in front of the scorpion.
- Nudge it from any side using a brush or pen.
- The scorpion will turn around to face the “threat.”
- Nudge and slightly push it until it backs up onto your hand.
- Avoid pressing it down since scorpions dislike it. DO NOT ever pick them up by the tail or touch them from the rear.
Remember that scorpions are not harmless pets and should be treated with caution and respect.
Breeding Flat Rock Scorpions
While the breeding process of Hadogenes troglodytes resembles that of other scorpions, breeding them in captivity can be rated as moderately challenging. This is primarily because they have a long maturation period, and the pregnancy process itself is quite lengthy.
Maturity:
Hadogenes troglodytes grows very slowly. On average, it takes 8 – 10 years to reach adult size.
Adult specimens can be recognized by the presence of a large lobe at the base of the pedipalpaltarsus.
Sexing
Unless fully grown, Flat rock scorpions are very difficult, if not impossible to identify by virtue of their external morphology.
- Size and shape. Males are larger and are more slender than those of females.
- Pectinal teeth. According to the study, the pectinal teeth counts for troglodytes vary between 22 and 28 in males and 18 to 22 in females.
- Genital operculum. In females, it opens as a single flap while in males the operculum consists of two unconnected sclerites which can open independently.
- Metasoma. Males have significantly longer metasoma than females. The sides of the tail are smooth in females but bumpy in males.
- Mesosoma. In males, the back part of the body has very fine bumps, while in females, it’s very shiny. In males, the seventh segment is as long as it is wide, while in females, it’s wider than it is long.
- Telson: The underside of the tail is finely bumpy in males and slightly bumpy in females.
Mating:
Before placing a pair of adult scorpions together, it is important to ensure that they are well-fed. The container in which mating will occur should be spacious enough to accommodate a piece of flat stones to which the male can attach the spermatophore.
- the male uses its pedipalps to grasp the female’s pedipalps to guide the female over a spermatophore during mating;
- the female usually follows the leading male in a classical promenade until a suitable spot is found for spermatophore deposition;
- then, the male assists the female in positioning her genital aperture over the spermatophore;
- after that, the pair separates.
Note: During mating, the male can sting the female as a part of the courtship ritual.
Keep in mind that Hadogenes troglodytes are very territorial and after mating females can fight males right away. Therefore, be ready to intervene.
Gestation:
Depending on the temperature and feeding, females have gestation periods of up to 18 months.
Over the following months of pregnancy, her abdomen takes on increasingly round shapes. In the final months of pregnancy, the abdomen expands significantly, and the distance between the plates becomes noticeably wider. The highly stretched pleura, connecting the tergites and sternites, has a light gray color.
Scorplings:
Flat rock scorpions produce fairly small broods (10–30).
During birth, the female assumes a characteristic “basket” posture. She slightly arches her back, crosses her legs underneath her, and her “tail” is almost lowered, with most of it touching the substrate.
The young are born live and ascend their mother’s back. Unlike juvenile scorpions and adults, scorplings have suckers on their legs, which allow them to move confidently and easily cling to the mother’s body. They are white and relatively large.
Scorplings stay on their mother’s back for a few weeks. During this time, their bodies derive energy from the remaining yolk. After that, they start molting directly on their mother’s body.
After the second molt, they start resembling adult scorpions. Their exoskeletons are still soft and nearly white, gradually darkening later.
Approximately 7-10 days after becoming fully hardened, scorplings begin to leave the mother’s back and scatter. Once they climb down, they become completely independent.
Flat Rock Scorpions and Suitable Tankmates
None. It is not recommended to keep these scorpions with other scorpion species or even conspecifics. They will fight eventually.
In Conclusion
Flat rock scorpions are very undemanding and easy to care for, even for beginners. Basically, they prefer hot and dry conditions and require a snug-fitting hide.
At the same time, these scorpions are not active. So, if you were looking for something to be constantly moving, then this is not the pet for you.
Flat rock scorpions can be extraordinary companions for many years! However, it’s essential to remember that acquiring these animals requires a significant commitment.
Related Articles:
- The Most Popular Scorpion Species Suitable As Pets.
- Emperor Scorpion – Detailed Guide: Care, Diet, and Breeding
References:
- Newlands, Gerald. “A revision of the scorpion genus Hadogenes Kraepelin 1894 (Arachnida: Scorpionidae) with a checklist and key to the species.” PhD diss., North-West University (South Africa), 1980.
- Newlands, Gerry. “A re-examination of some southern African scorpion species (Arachnida: Scorpionidea).” Annals of the Transvaal Museum 26, no. 10 (1970): 199-210.
- PRENDINI, Lorenzo. “On HadogenesangolensisLourenço, 1999 syn. n Zhong, Jie, Xian-Chun Zeng, Xin Zeng, Yao Nie, Lei Zhang, Shifen Wu, and Aorigele Bao. “Transcriptomic analysis of the venom glands from the scorpion Hadogenes troglodytes revealed unique and extremely high diversity of the venom peptides.” Journal of proteomics150 (2017): 40-62.
- Fet, V.I.C.T.O.R. “Family Ischnuridae Simon, 1879.” Fet, WD Sissom, G. Lowe, and ME Braunwalder, Catalog of the scorpions of the world (1758–1998)(2000): 383-408.
- R.S. De Voe. Captive invertebrate nutrition. Vet Clin North Am ExotAnimPract. (2009).
- Veterinary Care of Scorpions. 2017, Journal of Exotic Pet Medicine.
- Newlands, G. “Ecological adaptations of Kruger National Park sgop. pionids (Arachnida: Scorpionides).” Koedoe 15, no. 1 (1972): 37-48.