The Desert Hairy Scorpions, also known as the Arizona Giant Hairy Scorpions (scientifically named Hadrurus arizonensis), are fascinating animals that inhabit the southwestern United States and northern Mexico.
Hadrurus arizonensis has become a popular subject of interest and curiosity among many hobbyists due to its impressive size, distinct appearance, and ease of care. Keeping these scorpions in captivity requires providing them with a deep substrate, warm temperatures, and low humidity.
In this article, I will delve into the unique characteristics, behavior, and natural habitat of the Desert Hairy Scorpion, as well as discuss the challenges that hobbyists may encounter when caring for them.
Quick Notes about Desert Hairy Scorpion
|Name||Desert Hairy Scorpion|
||Giant hairy desert scorpion, Giant hairy scorpion, or Arizona Desert hairy scorpion|
|Scientific Name||Hadrurus arizonensis|
|Tank size (minimum)||10 gallon (~40 liters)|
|Average size||3.5 – 4.5 inches (9 to 12 cm)|
|Optimal Temperature||75 – 95°F (24 – 35°C)|
|Water type||Freshwater bowl|
|Moisture||30 – 50 %|
|Substrate||6 – 8 inches (15 – 20 cm) deep|
|Life span||up to 25 years|
|Color Form||Yellowish brown|
Taxonomy and Etymology of Desert Hairy Scorpion
The word Hadrurus has Greek-Latin roots and consists of two words, ‘Hadr’ meaning ‘thick or stout’ and ‘Uro’ meaning ‘Tail. The Latin word ‘Hirsut’ meaning ‘hairy’.
The species name Arizonensis – the name of the place meaning “from or belonging to” (-ensis) and related to the state of Arizona, USA.
Basically, the name of this species can be freely translated to “Thick-tail scorpion belonging to Arizona”.
Distribution of Desert Hairy Scorpion
This species of scorpion is widely distributed in the southwest of North America (Arizona, California, Nevada, and Utah), and Mexico (Sonora and Mohave desert near Zzyzx).
Natural Habitat of Desert Hairy Scorpion
These scorpions are usually found in semi-arid and arid regions at heights ranging from 1000 – 2000 yards (900 to 1800 meters) and are especially adapted to hot and dry conditions, although it can also be found on sandy dunes.
The Desert Hairy Scorpions mostly hide in deep, complex burrows that they dig themselves, but can also be found under rocks, fallen trees, etc.
Description of Desert Hairy Scorpion
This is the largest scorpion in North America. Fully grown adult specimens can reach up to 5.5 inches (14 cm) in length, although on average, the size varies from 3.5 – 4.5 inches (9 to 12 cm) and weighs around 0.25 oz (7 gr).
Distinguishing characteristics of Hadrurus arizonensis:
- Two long and narrow pedipalps. This species has 3 “accessory” trichothria at the base of the movable finger of the pedipalp chela.
- Pedipalp fingers are light yellow; they are similar to palm in color.
- Brown setae (“hairs”) that cover its body which allow the scorpion to detect vibrations in the soil.
- Telson is hairy on all aspects, no externally visible oval glands on the dorsal surface of vesicle near origin of aculeus in mature males. Females are distinctly less hirsute than males.
- Posterior of the carapace and dorsum of mesosoma are usually dark olive or light yellow.
- The base color of the entire body is pale to deep yellow.
- Base color of cuticle pale to deep yellow.
- Pectine teeth range from 32 to 37 in males and 24 – 31 in females.
Lifespan of Desert Hairy Scorpion
Currently, there is no precise scientific data regarding the lifespan of this species of scorpion. According to a study conducted in 1966 by Stahnke, H. L., it was recorded that Hadrurus arizonensis can live up to 25 years.
Unfortunately, there is no additional data to confirm these findings yet.
Nonetheless, it is registered that in optimal conditions, these scorpions live for 10-20 years. They are long-lived even among scorpions.
Note: Their lifespan will greatly depend on the conditions they are kept in, how well you feed them, and how stressful the environment is for them.
Typical Behavior of Desert Hairy Scorpion
Nocturnal: In the wild, the Desert Hairy Scorpion is primarily active at night and spends most of the day hiding in burrows or other sheltered areas to avoid predation and the heat of the sun.
Solitary: These scorpions are solitary and do not form large groups or colonies like some other species.
|Even though according to the study, Hadrurus arizonensis does not appear to be highly cannibalistic and can be placed together for observation with little concern for a fatality for a long time, it is still not recommended. Keeping them in the community will always be a stress factor.|
Interesting fact: This species appears to discriminate between conspecifics and heterospecifics and avoid preying upon conspecifics. Behaviors of adults toward juvenile conspecifics are similar to interactions between adults, whereas hetero specifics were often captured and eaten.
Ambush predators: These scorpions are not active hunters. They are ambush predators and wait for prey to come within striking distance before attacking.
Burrowers: Although Hadrurus arizonensis is very adaptable and can survive in a variety of habitats, these scorpions do have a very strong preference to live in a burrow. They will generally excavate their own burrows if suitable natural ones are not available.
Note: It was documented that this species has been taken at a depth of 8 feet below the surface of the sand.
To do that, they scratch and kick loose sediment from the subsurface with the first two to three pairs of walking legs.
The subsurface biogenic structures produced consisted of sub-vertical ramps, U-shaped burrows, helical burrows, and maze works.
Messy: They can dig for hours non-stop. In addition, they are pretty strong to move the objects around their enclosure. As a result, they can completely transform your setup into something wild.
Shy: These scorpions do not venture into the open if they can hide somewhere. They can stay hiding for weeks.
Semi-aggressive: Hadrurus arizonensis is semi-aggressive, meaning they will not intentionally run at you trying to sting unless you pose an immediate threat to them (for example, grabbing their tail or pinning them down). In this case, they will react defensively when touched and do not hesitate to sting when annoyed.
Although, these scorpions do possess venom and can sting, but their natural tendencies are to hide and escape.
Grooming: Scorpions rely predominantly on mechanosensory and chemosensory organs to guide their orientation behaviors. Once these organs are affected by the presence of dirt such as clay or prey bodily fluid, scorpions may display a cleaning behavior to reduce or eliminate its influence on their sensory capabilities.
- Communal: No (with caution, still not recommended)
- Activity: Low
- Peaceful: Semi-aggressive
- Burrowers: Yes
- Venomous: Yes
Venom of Desert Hairy Scorpion
The venom of this species contains a mixture of neurotoxins and enzymes that can cause pain, swelling, and numbness at the sting site but it is not considered medical significant for healthy adults.
Nonetheless, it can still be dangerous for children and individuals who are allergic to scorpion venom or have compromised immune systems. Thus, if you are stung by a Desert Hairy Scorpion, it is important to seek medical attention immediately.
|DO NOT allow children to touch Hadrurus arizonensis!|
Interesting fact: Venom is metabolically costly. In scorpions, replenishment of the venom will raise the metabolic rate 39% over the basal metabolic rate in the first 3 days of venom regeneration.
Diet of Desert Hairy Scorpion
The Desert Hairy Scorpions are opportunistic predators and will consume almost any prey that they can subdue. Some of the common prey items for them include crickets, roaches, grasshoppers, beetles, small spiders, and even other scorpions.
They are ambush predators who detect prey when it comes within reach.
Unlike some other scorpions that have powerful and large pincers, they do not rely only on them to immobilize their prey. Instead, they use their pincers to grab their prey and then inject venom (at least once) with their stinger.
Interesting fact: prey is detected primarily by sensing vibrations with the pectine organs. The pedipalps have an array of fine sensory hairs that sense air-borne vibrations; the tips of the legs have small organs that detect vibrations in the ground.
In the terrarium, the acceptable food items include:
- dubia roaches,
- red runner roaches,
- worms, etc.
How Often to Feed Desert Hairy Scorpion?
Adults can be fed once a week. Young scorpions should be fed at an interval of 3–4 days.
Some Feeding Tips
- Time. Desert Hairy Scorpions are nocturnal animals. Therefore, it is highly recommended to feed them at night (at least in the evening). Therefore, 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. For example, adult scorpions can eat full-grown cricket (1 inch or 2.5 cm long).
- Prey activity.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.
- 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.
- 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.
|Important: Large prey may harm the scorpion. In captivity, you should never give them prey that can fight back aggressively.|
Feeding Problems with Desert Hairy Scorpion
You are unlikely to encounter any issues with this species in general. However, if you do experience any problems, consider the following factor that could be the cause:
- Shipment stress: If you have recently acquired the scorpions, give it time to adjust to their new environment.
- Molting preparation: (The most common one) Prior to molting, their eating habits can change dramatically, with a sharp decrease in appetite. Eventually, they may stop eating altogether.
So, if your scorpion looks like a bloated barrel, there is a high likelihood that it is preparing to molt. Don’t worry and stop feeding it. After all, you do not want the prey to harm or even eat your molted scorpion.
- Lack of hunger: Due to their low metabolism, scorpions can survive without food for months.
- Low temperature: When the temperature falls below the optimal range, Desert Hairy Scorpions become very lethargic.
- Diet Type: Carnivore
- Food Preference: Alive prey.
- Feeding Frequency: 1 time a week (for adults) and 2 times a week (for babies)
|Desert Hairy Scorpions need alive prey. So, if you are a sensitive person, you should not keep them as a pet.|
Keeping and Housing Desert Hairy Scorpion
Despite the fact that this species of scorpion is not particularly demanding and may even be recommended for beginners, it is important to understand that like all living organisms, this species has its own requirements and preferences.
The better you can meet and satisfy these needs, the healthier and happier your pet will be.
That is why if you have decided to keep Hadrurus arizonensis as a pet, you should first create appropriate conditions before acquiring it, rather than the other way around.
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)
|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)
|It is made of ecological materials.||Some models have problems with ventilation|
|Looks very nice||High cost and weight|
3. Aquarium (so-so)
|It is made of ecological material (glass)||There can be problems with the ventilation|
|Very easy to buy||Fragile|
Tank Size (Enclosure):
Although many breeders keep Hadrurus arizonensis in small containers, claiming their inactivity and tendency to hide as reasons, this argument is weak if your goal is to provide the best conditions for them.
Given that these scorpions can grow considerably large and need a temperature gradient, where one section of their enclosure is warmer than another, I believe a 10-gallon (about 40 liters) enclosure would be optimal for one fully grown adult.
Tip: Long enclosures are better than tall ones of the same size. They need mostly a place to crawl from side to side, not up and down.
|Important: Although The Desert Hairy Scorpions do not climb very much, any enclosure should be escape-proof anyway. After all, you do not want them crawling in your house.|
No special requirements.
Desert Hairy Scorpions are nocturnal. Thus, ambient light will be enough.
|UV lighting warning: Like other scorpions, they give off an amazing fluorescent bluish-green appearance under UV light (‘Blacklight’). Therefore, people often use this kind of lighting.
This is wrong.
It has also been reported that UV lighting is not completely safe for scorpions.
If scorpions were kept under a constant UV source, fluorescence disappears in about 2 weeks. Fluorescence reappears if the scorpion is removed from UV. This fact suggests that the substance responsible for fluorescence is UV sensitive and breaks into components that are not fluorescent. Secondly, this suggests that there is a constant production of the substance in the cuticle as a secretion (it may be a metabolic product of some physiological process) property of the cuticle.
It can cause damage to the outer layers of their exoskeleton (eventually, causing molting problems).
UV light can be used only for short periods of time or as 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.
Interesting fact: According to some studies, it appears that scorpions do not detect red light.
Thus, use red light instead. It also gives good heat.
The ideal temperature range for these scorpions falls between 75 – 95°F (24 – 35°C). If temperatures drop below this range, their metabolic rate slows down, and they may become sluggish. Conversely, temperatures above 35°C can cause rapid dehydration in these creatures.
Interesting fact: Scorpions are able to withstand considerable dehydration (30% to 40% of their body weight) and apparently tolerate the increased hemolymph osmotic pressures and ionic concentrations until body fluids can be replenished.
Desert Hairy Scorpions can tolerate high temperatures, for example, experiments showed that approximately 25 % mortality occurred after 6 hours under 111°F (44°C).
In addition to maintaining the appropriate temperature range, it is important to replicate the seasonal changes that these scorpions experience in their natural habitat.
Between November and April, external temperatures typically decrease (68-74°F (20 – 23°C) in the winter), causing scorpions to seek refuge in their burrows and become semi-dormant. To promote optimal health in captivity, it is recommended to simulate this behavior by providing suitable hideouts and a slightly cooler environment during the winter months.
- 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 scorpion there.
Maintaining a humidity level between 30 and 50% is recommended for the optimal health of Desert Hairy Scorpions.
It is important to note that high humidity levels can have a negative impact on their well-being. These scorpions are particularly sensitive to high humidity and are susceptible to fungal infections (mycosis – black patches) if their environment is excessively damp.
Therefore, it is crucial to keep their enclosure as dry as possible to prevent the growth of harmful microorganisms.
Note: Do not ever spray/mist scorpions, it freaks them out and they really hate it.
Desert Hairy Scorpions are known to dig burrows up to 20 inches (50 cm) deep and even deeper. This highlights the importance of providing a suitable substrate that allows for natural burrowing behavior and proper hiding places for your scorpion.
These scorpions should not have loose substrates! They need to burrow!
Note: It is not recommended to use a cocofiber/sand mixture as the clay/sand mixture makes stronger burrows and the ability of cocofiber to retain humidity is not necessary for these scorpions.
Instead, it is suggested to use a 60/40 or 70/30 sand/excavator clay mixture. Adding too much clay will make it difficult for them to dig, while too little may cause tunnel collapses. Play sand can be used, but make sure it is only sand with nothing else mixed in.
- Mix the sand and clay together, put it in the tank,
- Pour some water,
- Pack it down as tight as possible.
- Let the substrate dry by layers of about 2 inches (5 cm) for quicker drying.
- Avoid cracking the glass at the bottom of the tank when packing down the sand.
Once it dries, the substrate is ideal for Hadrurus arizonensis to build burrows. Keep in mind to have at least 6-8 inches (15-20 cm) of substrate eventually, as the more substrate provided, the happier your scorpion will be.
Scorpions, particularly those living in hot and dry environments, face significant challenges when it comes to water conservation. In order to adapt to these conditions, they have developed a range of behavioral, morphological, and physiological mechanisms to limit water loss.
Research has shown that water-loss rates decrease with increasing body size in Hadrurus scorpions. Interestingly, the highest and most variable rates of water loss occur in early instars and sub-adults, with no significant correlation between water loss and body size for scorpions weighing over 4 g.
Interesting fact: Regardless of their hydration state, water uptake from a subsaturated atmosphere or moist substrate plays little or no role in the water economy of Hadrurus arizonensis.
Desert Hairy Scorpions have one of the lowest rates of water loss, losing only 0.028% of their body weight per hour in dry air at 86°F (30°C).
Although these scorpions primarily obtain their hydration from prey items, it is still highly recommended to provide a water dish for these scorpions.
Note: Plastic bottle caps, oyster shells, or seashells will also suffice.
To prevent sand from filling up the water dish, it is best to install a raised dish. Fill the dish 1-2 times a month and let it evaporate dry.
Note: Water dish does not cause mycosis, only high humidity does.
Burrowing space is an essential requirement for Desert Hairy Scorpions – any other hides, and shelters cannot compensate for it. Burrowing is an instinctual behavior that fulfills their need for security and comfort.
A tight-fitting hide will encourage the scorpion to burrow and create more room for itself. You can also create dark hiding spots using rocks, coconuts, cork bark, or any other suitable material that enables the scorpion to conceal itself completely.
If you plan to house several scorpions, it is crucial to provide each of them with a hiding place in different parts of the enclosure to make them feel secure.
Remember, providing adequate burrowing space and hiding places is critical to keeping Desert Hairy Scorpions healthy and happy in captivity.
Examples of Tank Equipment
Handling Desert Hairy Scorpion
Desert Hairy Scorpions is a venomous species. They 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 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.
Remember that scorpions are not pets and should be treated with caution and respect.
What is a bioactive enclosure for Desert Hairy Scorpions?
A bioactive enclosure is a remarkable example of a self-sustaining ecosystem that requires minimal maintenance. It comprises various living organisms that coexist harmoniously within a tank such as Asbolus verrucosus (Blue Death Feigning Beetles), Cyptoglossa variolosa (Grey Death Feigning Beetle), and a few others.
These insects primarily serve the purpose of cleaning after the scorpions. They are detritivores that recycle dead organic matter, including scorpion excreta. Additionally, these tiny bugs play a crucial role in maintaining a healthy environment by regulating mold and decaying matter.
Warning: However, caution must be exercised when selecting such species for a bioactive enclosure.
Breeding Desert Hairy Scorpion
Although Hadrurus arizonensis is commonly kept as pets because they are hardy and easy to care for, captive breeding of these scorpions has proven to be a bit difficult (they either refuse to mate or females reject spermatophore, yes they can do that), which has led to the continued capture of wild specimens for the pet trade.
Desert Hairy Scorpions are ovoviparous, meaning they give birth to live young rather than laying eggs. Females provide limited maternal care for their offspring, typically only until the young have completed their first molting cycle. After that, the juveniles are on their own and must fend for themselves.
Hadrurus arizonensis has long been viewed as non-dimorphic in characters other than the pectines.
- Pectine teeth range from 32 to 37 in males and 24 – 31 in females.
Although some scientists suggested that adult males possess a longer metasoma than females, others have questioned the validity of this claim. They argue that a more comprehensive analysis is required, one that goes beyond simply examining raw data. Such an analysis should involve the use of ratios and statistical tests to enable a more robust comparison between the sexes.
For example, some tests showed that adult females and males exhibit sexual dimorphism in some but not all body components.
- Females had significantly larger prosomas, averaging 2.06%, 1.52%, and 3.37% larger in length, width, and area, respectively.
- Males had significantly larger Chela L (2.17%), Met 1 L (5.33%), Met 5 L (6.57%) and Met 5 W (1.74%), Met L (7.81%), Tot L (2.89%), and Pec L (17.09%).
The remaining characters were not significantly different between the sexes (<1% difference).
Desert Hairy Scorpions need 3-4 years to become mature. Generally, it takes them 7 molts.
Hadrurus arizonensis is a polygamous species that uses external sperm transfer through a spermatophore. Studies have suggested that both males and females exhibit mate choice (towards larger partners), indicating that individuals of this species are not randomly mating.
There are 4 behavioral phases:
- Initiation. If the female is receptive, the male grasps her pedipalps, first in the region of the femur or patella and later his pedipalp fingers are closed over hers. At the same time, he can sting or club her from under 1 to up to 35 min. Males may sting the female from 1 to 14 times in a single mating interaction.
- Promenade a deux. The pedipalp-to-pedipalp grip includes forward, backward, and sideways walking. The promenade can last from under 40 min to over a day.
- Sperm transfer. Once the pair has located a solid surface (such as a stick or rock), they may pass over it multiple times and in several different directions before the male finally stops to deposit the spermatophore.
- Termination. Male releases the female.
Desert Hairy Scorpions do not exhibit post-mating cannibalism.
Interestingly, male scorpions require 4-5 days to produce spermatophores between mating attempts. This suggests that the process of courtship and copulation is energetically demanding for male scorpions compared to their female counterparts.
The gestation period of this species can vary greatly depending on the temperature, with a potential duration of up to 1 year.
As the time of parturition approaches, females become very secretive and agitated. They will sting at the slightest provocation.
Scorpions are ovoviparous. The young break out of the egg membrane and crawl upon the female’s back.
Desert Hairy Scorpions give birth to 20 – 36 neonates (generally called Nymphs or Scorplings).
Females usually give birth in the burrow and the first instar larvae stay on the mother’s back until the first molt (up to 16 days), at which time they disperse as second instars.
During this period, there is no need to feed baby scorpions, their mother will take care of that. Just give her more food than you normally would. She will catch the prey, tear it apart and let the babies feed on it.
As in most other scorpion species, about a week after the first molt, the second instars scorplings start leaving their mother’s back.
Once the scorplings have left their mother’s back, it is important to separate them from both their mother and each other.
Note: If you had moved a gravid female to a separate tank while she was carrying her young, it is not advisable to transfer her back immediately after the scorplings have left her back. She may be very hungry and aggressive towards other scorpions at this point.
It is important to note that scorplings require a lot of nutrition at this stage, as they are often too weak to capture prey and may resort to cannibalism. They do not need a large amount of space and can be housed in small food storage containers with proper ventilation.
When it comes to their diet, baby scorpions require the same food as adult scorpions, but in smaller sizes. Suitable food options include:
- small pinhead crickets (¼ inches or 0.5 cm long),
- small worms,
- moths, etc.
It is essential not to give them prey that is too large for them to catch.
Furthermore, baby scorpions require more frequent feeding compared to adults, ideally 2-3 times a week. It is unnecessary to provide water dishes for baby scorpions.
The Desert Hairy Scorpion (Hadrurus arizonensis) is a fascinating species that requires specific care to thrive in captivity.
Providing the right substrate (dry and deep), humidity (low), and temperature range (warm) is crucial to keep them healthy and active.
With the information provided in this article, anyone can provide a suitable environment for the Desert Hairy Scorpion and enjoy the benefits of observing their unique behavior and features.
It is also essential to remember that it is a venomous and semi-aggressive species. Handling should be avoided, especially for inexperienced individuals, to prevent potential harm.
- The Most Popular Scorpion Species Suitable As Pets.
- Emperor Scorpion – Detailed Guide: Care, Diet, and Breeding
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- Tallarovic, Sara Kathleen. Reproductive and aggressive behaviors in the giant hairy desert scorpion. Oregon State University, 2000.
- Williams, Stanley C. “Systematic revision of the giant hairy-scorpion genus Hadrurus (Scorpionida: Vejovidae).” In Calif Acad Sci Proc. 1970.