Asian Forest Scorpion (Heterometrus sp.) is an excellent choice for hobbyists seeking a new, fun, and exotic pet to add to their tanks. Actually, lots of people use their aquariums as terrariums (or paludariums) to keep terrestrial invertebrates as well.
Asian Forest Scorpions are highly tolerant animals, very adaptable to various habitats, and very easy to care for even for beginners. They do not need much to survive and can thrive for years under favorable growth conditions.
So, if you have never kept a scorpion before but you are interested in it or simply want to learn more about these unique creatures, you have come to the right place.
In this guide, I will share some practical tips and take you through everything you need to know on how to take care of them and should you choose Asian Forest Scorpions as your pets.
Quick Notes about Asian Forest Scorpions
|Name||Asian Forest Scorpion|
||Asian black scorpion, Large Philippine forest scorpion, Malaysian black scorpion, Rainforest scorpion, the Giant forest scorpion, or the Giant black scorpion|
|Scientific Name||Heterometrus sp.|
|Tank size (minimum)||10 gallons (~40 liters)|
|Average size||4 – 6 inches (10 – 15 cm)|
|Optimal Temperature||75 – 90 °F (24 – 32 °C)|
|Water type||Freshwater bowl|
|Moisture||70 – 80 %|
|Substrate||3 – 6 inches (7 – 15 cm) deep|
|Life span||up to 10 years|
|Color Form||Brown to black|
Etymology of Asian Forest Scorpions
The word ‘Heterometrus’ came from the Greek word ‘Héteros’ meaning ‘Different or other’ and the Greek word ‘Metrus’ = ‘Measurement’.
- Heterometrus silenus was named after Seilēnós (Σειληνός), a god of the forests in Greek mythology.
- Heterometrus glaucus. Glaucous came to English – by way of Latin ‘Glaucus’—from Greek ‘Glaukos’, meaning “Gleaming, gray or blue-grey’.
- Heterometrus laevigatus. Named after the Latin noun “laevigatus”, smooth and lightened.
- Heterometrus longimanus. Longimanus translates from Latin as ‘long hands’ ([longi- (long) + manus (hand)].
- Heterometrus spinifer. Spinifer is from ‘Spīna’, meaning ‘Thorn, spine, prickle’ + ‘-fer’ (‘Carrying or bearing’).
- Heterometrus thorellii. This species was named in honor of Swedish arachnologist Tord Tamerlan Teodor Thorell.
- Heterometrus laoticus. These scorpions are found in peaty areas of Vietnam and Laos. Thus they got the name ‘Laoticus’.
- Heterometrus petersii. This species was named in honor of German zoologist Wilhelm Carl Hartwig Peters.
Distribution of Asian Forest Scorpions
Scorpions of the genus Heterometrus are found in the Philippines, Vietnam, Cambodia, Thailand, Malaysia, Indonesia, Singapore, India, Myanmar, Laos, and China.
Of course, some species have limited distribution, for example, Heterometrus laoticus is mostly located in Vietnam and Laos.
Natural Habitat of Asian Forest Scorpions
Asian Forest Scorpions are terrestrial tropical animals that usually can be found in the tropical rainforests burrowed underground, below trees, and in leaf litter.
They are exceptionally biodiverse creatures and can utilize and adapt to various microhabitats to survive.
Description of Asian Forest Scorpions
These scorpions grow pretty big. Fully grown adult Asian Forest scorpions can reach up to an impressive 6 – 8 inches (15 – 20 cm). However, it’s quite rare to find one of that size.
Generally, the average size of adult scorpions is often about 4 – 6 inches (10 – 15 cm) long.
The coloration is mostly dark. However, depending on the species, it may also vary from light brown to almost black.
Interesting fact: If you put them on the sunlight their body will have some kind of greenish bluish tint to it.
They have a well-developed and very powerful pair of pincers (pedipalps) which they use to catch prey.
Asian Forest scorpions have very bad eyesight. Instead, they rely on sensory organs – little tiny hairs on their body, pincers, tails, and legs.
Lifespan of Asian Forest Scorpions
Currently, there is no data available on the maximum lifespan for these scorpions.
However, if you provide your Asian forest scorpions with the best care possible and meet all of their needs, you could have your pets for at least 5 to 10 years in captivity.
There is no difference in age between the male and the female Asian forest scorpions.
Note: Lifespan is likely shorter in the wild because of diseases, predation, and poor living conditions.
Typical Behavior of Asian Forest Scorpions
Fully grown Asian forest scorpions are one of the few species that can relatively safely cohabit with minimal aggression or cannibalism. While cannibalism does occur, it is rare and mostly between young scorpions when they do not have enough food or are limited in space.
|Although it is possible to keep this species communally it is still not considered a good idea. Even a small risk of aggression should be eliminated if you want to keep them healthy and happy.|
They are very skittish and would prefer to go and hide under logs, stones, leaves, or whatever’s inside the enclosure.
Normally, Asian forest scorpions react defensively when touched. In most cases, they try to escape or show defensive postures. Even When they are very annoyed they rarely sting and prefer to pinch.
Note: Scorpions respond by pulling the claws towards the mouth, erecting the tail, and scuttling backward (defensive withdrawal).
Males get along better than females. After delivering its young, the female’s behavior changes drastically, they become territorial, and instead of running away they grasp or may even try to sting.
Their activity can be divided into three states: (1) action, (2) alert immobility, and (3) relaxed immobility.
They are strictly nocturnal animals and rarely come out during the day. The pick of their activity starts at dusk and stops during the night, before sunrise.
According to the study, Asian forest scorpions are most active during the first 4-5 hours of the dark period (locomotion, 14.5 min/h; twitches, 11 min/h). It should not be a surprise since scorpions have one of the lowest metabolic rates ever recorded.
Asian forest scorpion is a moderate burrowing species. It means that they do not dig all the time but when they do they can burrow very deep.
- Communal: Yes (with caution, still not recommended)
- Active: No
- Peaceful: Yes (generally)
- Burrowers: Yes
- Venomous: Yes
Venom of Asian Forest Scorpions
Asian forest scorpions are more of a pincher scorpion, their venom is exceptionally mild and it should not cause too much problem (if any) for healthy adults. Something like a bee sting or even weaker.
Nonetheless, some people may be allergic to their toxins and their venom can cause intense localized pain: redness, swelling, and itching can occur as well. In this case, if you get stung, you need to get to the hospital ASAP.
According to the study, the death reports regarding the scorpion sting are not available except for a few reports in children and infants.
Interesting fact: Scorpions can sting many times, but their venom becomes depleted with each sting.
Diet of Asian Forest Scorpions
In the wild, Asian forest scorpions are considered to be generalist predators on a variety of prey, such as insects and other small animals they can capture and overpower, such as:
- small vertebrates like lizards, snakes, frogs, and rodents.
They use sensory systems (long and very thin sensory hairs located all over the body) other than vision to locate prey.
- Once Asian forest scorpions attain a certain size and become strong enough, they only use their claws to dispatch any normal prey item. Whereas young may try to sting prey as well.
Note: This is, probably, because venom production may be costly from an energetics standpoint and large prey items are often rejected in favor of smaller items that do not require stinging.
- Adult scorpions can easily survive without food for over several months.
|Important: Large prey may harm the scorpion. In captivity, you should never give them prey that can fight back aggressively.|
In the terrarium, the acceptable food items include:
- red runner roaches,
Note: Some hobbyists say that Asian forest scorpions should not be fed with cockroaches because their digestive system cannot ingest their exoskeleton very well. Well, I could not find any documented reports or studies regarding this problem. It seems more like a myth to me.
How Often to Feed Asian Forest Scorpions?
Adults can be fed once a week as it was observed that, in most cases, they do not consume their food when supplied at an interval of 3–4 days
Some Feeding Tips
- Time. Asian forest 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. Asian forest scorpions are not active hunters. They will not pursue their prey. Like most scorpion species, they prefer to wait for their moment. 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.
- Scorplings. Young scorpions can be too weak to overpower their prey. However, they will consume the crickets that have just died.
- 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.
Feeding Problems with Asian Forest Scorpions
Some hobbyists complain that their scorpions stopped eating for weeks. This often happens right after purchase. Some potential reasons include:
- Shipment stress. Give them time to adapt to their new home.
- Preparation for a molt. Changes in their eating habits change drastically before molting. You will see a sharp decrease in appetite. They may start eating less and eventually stop eating altogether.
- Not hungry. Scorpions have a very low metabolism and can live without food for months.
- Low temperature. When the temperature drops, Asian forest scorpions become very lethargic.
However, in some cases, we can have the opposite problem – a scorpion becomes so fat that it looks like its body squeezing out of its exoskeleton.
- Diet control. Check its diet. You are giving them way too much.
- Gravid female. Make sure that your scorpion is not a gravid female. In this case, you will also see a little bit of white space between each carapaces and the pleural membrane will be exposed. This is normal.
- Diet Type: Carnivore
- Food Preference: Alive prey.
- Feeding Frequency: 1 time a week (for adults) and 2 times a week (for babies)
|Asian forest scorpion usually eats the prey alive. So, if you are a sensitive person, you should not keep them as a pet.|
Keeping and Housing Asian Forest Scorpions
Currently, there are several different scorpion species being raised in captivity under the name Asian forest scorpion. Fortunately, their requirements for living conditions are approximately the same.
Even though these scorpions are very hardy and beginner-friendly, there are still many important factors that must be considered when caring for them if we want our pets to thrive.
To put it in a nutshell, we need to emulate their natural environment meaning: high humidity, warm temperature, lots of hiding places, and substrate that allows them to burrow.
Remember, in the wild, Asian forest scorpions are usually found burrowed underground, below trees, and in leaf litter.
First of all, you will need to choose an enclosure that provides the appropriate levels of heat and humidity for Asian forest scorpions. There are several options here.
|It is made of ecological material (glass).||There can be problems with ventilation|
|Good for humidity.|
|Very easy to buy.|
|It is made of ecological materials.||Some models have problems with ventilation|
|Good for humidity.||High cost and weight|
|Some models have good ventilation|
3. Plastic container.
|Cheap.||Plastic is not the most ecological material, especially in hot temperatures.|
|Good for humidity.||Nor 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).
|Important: Although Asian forest scorpions do not climb very much, any enclosure should be escape-proof anyway. After all, you do not want them crawling in your house.|
Tank Size (Enclosure):
There is a lot of conflicting information regarding this question.
On the one hand, some hobbyists think that because Asian forest scorpions grow big they will also require large tanks. On the other hand, some people use very small tanks and say that they do not have any problem with that.
In my opinion, the tank size depends on 2 main factors:
- Size of the scorpion.
Personally, I would not recommend keeping young scorpions together because of potential cannibalism. Thus, each of them should have an enclosure that is at least 3-4 times larger than their size. It should be enough to create at least one hiding place for them.
Note: Do not keep them in little tiny boxes, as some people do. Sure, your scorpions will survive but will they be happy?
As for the adult Asian forest scorpions, the minimum recommended tank size for one individual is a 10-gallon (40-liter) tank. A pair of adults will require at least 15 gallons (60 liters).
Having a larger tank is always preferable because it can be easier to make diverse areas for them to hide.
Tip: Long tanks are better than tall tanks of the same size for keeping Asian forest scorpions. They need mostly a place to crawl from side to side, not up and down.
No special requirements. Asian forest scorpions are nocturnal creatures, they are very sensitive to light and used to live with very little light. Basically, you do not need it.
However, if you have plants, lighting should be adapted to their needs.
|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.
UV lighting is not completely safe for Asian forest scorpions. Ultraviolet is a part of the light from the sun, its rays can cause damage to the outer layers of their exoskeleton (eventually, causing molting problems). That is why they do not like to be exposed to the sun.
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.
The optimal temperature range for Asian forest scorpions is between 75 – 90 °F (24 – 32 °C). They do love warm temperatures.
Is it possible to keep that at 68 – 72 °F (20 – 12 °C)?
Well, yes, it is. However, you need to understand that at lower temperatures, their metabolism also slows down and all movements get slower. They may require supplemental heating if you have a cold house.
Note: Scorpions are cold-blooded animals. It means that they do not have control of their heat balance. Thus, their body temperature varies with the temperature of the environment.
|Important: Heaters should never be placed under their enclosure because they can overheat your substrate and burn or kill burrowed scorpions there.|
The best (safest) option will be to put the heater to the side of the enclosure, ideally, above the substrate line to heat the air as well.
Note: It is important to also use a thermostat to help moderate the temperature and keep it in the desired range.
Humidity levels are very important. The humidity level should be more than 60%. In ideal range would be between 70 and 80 % all the time.
Keep one part of the enclosure a little bit more damp by gently watering the substrate. It will give your scorpion the choice of where it would like to be at this or that moment.
Tip: One of the easiest ways to keep the humidity up is to use lots of sphagnum moss inside their enclosure.
Note: Do not spray/mist scorpions, it freaks them out and they really hate it.
Asian forest scorpions need freshwater. So, it is important to provide them with a shallow dish that they can easily crawl out of.
They do not need much, because they can hold on to the water for a very long time!
|Some hobbyists may disagree with me by saying that these scorpions get most of their hydration from eating prey items. In addition, they do not need any dishes because even little water droplets on the side of the container will be enough for them.
It is true.
Nonetheless, having a water dish helps to maintain humidity. Also, it is always better to provide something extra for our pets.
Ideally, we need to give them something like bottled spring water. But if you decide to use tap water, let it age for 24 hours before using it. Tap water contains chlorine and it can be toxic to them.
- Do water changes every 5 – 7 days.
Their enclosure should be filled with a substrate into which they can burrow. Asian forest scorpions burrow to chill, rest and hide.
|The general rule of thumb is that the substrate should at least equal the length of the scorpion itself. If your setup allows you should always opt for deeper!
Young scorpions do not dig much whereas adults require more depth (5 – 6 inches or 12 – 15 cm deep minimum).
Interesting fact: Asian forest scorpions are very sensitive to substrate vibrations.
The substrate should always be kept moist enough. It means that it should hold its shape when you squeeze it. However, not so wet that it drips or pools water.
Some popular choices of the substrate:
- coco fiber (Eco earth),
- peat moss,
- organic topsoil,
- Jungle mix soil,
- Zoo Meds Creatures Creature soil,
- The Bio Dude Terra.
It is also possible to use a combination of different substrates, for example:
- coco fiber and sand and (5:1 ratio). It is easy to maintain and it holds moisture very well.
- a mixture of peat moss and organic topsoil (1:1 ratio).
Do not use only sand! Sand often becomes supersaturated even though the top couple of inches are completely dry.
How often should we change the substrate?
Compared to many other animals, scorpions do not produce a lot of waste. Therefore, there is no need to change it very often. I know for sure that many hobbyists do not do it at all unless there is an outbreak of mold or fungi.
Nonetheless, in my opinion, it is still better to do it at least every 6 months.
There should be plenty of dark areas for them to hide in and these should be created out of rocks, driftwood, plants, coconuts, pieces of cork bark, etc. It will make them feel like they are still in the Asian rainforests.
- If you are planning to house several Asian forest scorpions, each of them needs a hiding place to feel secure in different parts of the enclosure!
- As for the plants, it’s highly recommended that you do use hardy plants. These scorpions are pretty strong to move them around. In addition, they can easily uproot them.
You need to do it ever 2 – 4 months.
Examples of Tank Equipment (examples with links to check the price on Amazon)
Handling Asian Forest Scorpions
Asian forest scorpions are venomous invertebrates with powerful pair of claws, so you need to handle your scorpions with utmost care. They are not pets you can play with!
Make sure children do not provoke the scorpion. It is against ethics and provoking the scorpion has its consequences.
Do not take them out just because you want to. You should really handle him as little as possible. They do not benefit from being handled and get stressed very easily.
Nonetheless, if you want/need to take them, it will be better to use rubber gloves:
- put your hand in front of the scorpion,
- nudge it from any side with a brush (pen, etc.),
- the scorpions will turn around to face the ‘threat’,
- nudge and slightly push it until it will back up onto your hand.
- Asian forest scorpions may behave defensively but they will not attack once they are in your hand.
- DO NOT press them down, they hate it!
Asian forest scorpions are more likely to pinch you than sting you. They can give a nasty bite and even break the skin of a human. As a result, you can flick your hand instinctively and your pet will go flying somewhere.
Asian forest scorpions can get hurt easily, even with their hard shells.
|Some people claim that their scorpions can recognize them and eventually become docile once they know food comes from you.
Personally, I do not think so.
Scorpions are not very smart animals, they, generally, operate on their instinctual nature. They do not understand and cannot learn, because they do not have long-term memory, – this is just beyond their abilities and nervous system.
Breeding Asian Forest Scorpions
Asian forest scorpions reach sexual maturity in the 2nd to 3rd year. Generally, it takes them from 6 to 7 molts to reach maturity.
Although these scorpions exhibit sexual dimorphism, it can be really hard to see for the untrained eye.
- You have to look at their undercarriage behind the walking legs to find two little feathers (pectines). In males, pectines (the sensitive organs) are longer and more feathery. Females have comparatively smaller and less feathery pectines as compared to males.
On the Internet, you may also find that the males of Asian forest scorpions tend to have longer tails and larger claws than the females. However, the females have a greater total length and a wider abdomen.
Well, this is not completely true.
According to the studies, most Heterometrus species are not sexually dimorphic in their claws or tails. For example,
- Heterometrus spinifer does not have a difference in claws.
- In Heterometrus longimanus, the males have slightly narrower and longer claws but it is also slightly lobiform in the females.
- In Heterometrus petersii, the males will have an enlarged tooth on the moveable finger of the claw and females will not have that.
Mating and fertilization:
According to the study, the main structure of the courtship in different species of Asian forest scorpions is similar:
- the male uses its claws 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.
Females have gestation periods up to 9 – 12 months and produce fairly small broods (20–40).
Note: It is recommended to separate the male and the female as a mother scorpion becomes highly defensive.
Scorplings are incapable of living separately from the female until their first molt. The mother carries the entire brood on her back.
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.
Tip: To improve the survival rate of scorplings, keep you temperature between 79 – 86°F (26 – 30 °C) and humidity above 80%.
Once scorplings leave its parent back, it will be better to separate them from the mother and each other as well.
|At this stage, they need a lot of nutrition. Considering the fact they are often too weak to overpower their prey they can start cannibalizing fast.
Generally, females of Asian forest scorpions do not hunt down their offspring. Nonetheless, natural predation can still happen. Therefore, the second instar scorplings should be separated from the mother.
They do not require a lot of space and can be kept in small food storage containers with adequate ventilation (just make small holes in the plastic). Provide them with damp substrate and hiding spots.
Baby scorpions have the same diet as adult scorpions but in smaller size:
- small pinhead crickets (¼ inches or 0.5 cm long),
- small worms,
- moths, etc.
Do not give them large live prey they cannot catch! It is recommended to feed them more frequently compared to adults – 2 times a week.
What is a bioactive enclosure for Asian forest scorpions?
This is a self-sustaining ecosystem that does not require any (or little) maintenance. It also includes living organisms that work together in a balance within a tank.
Generally, when hobbyists are talking about a bioactive enclosure for their scorpions, they mean that there will be isopods and springtails to clean after their scorpions. These little bugs help to keep mold and decaying matter under control as well.
Warning: Some species of isopods are protein hungry. It can be dangerous for molting scorpions because during this process they are completely defenseless until their skeleton fully hardens.
Therefore, if you are not sure, it is better to play safe and add only springtails. These insects are detritivores that recycle dead organic material including scorpion’s poop.
Asian forest scorpions are amazing and readily available species in the hobby. Their impressive size and fearsome appearance are highly prized by hobbyists.
These scorpions are easy to care for and can be recommended even for beginners. The biggest concern is that they are venomous animals. They are not pets to play with.
Having them as pets can be exciting but it is one big responsibility. After all, they can live for many years. So, the owner must do research beforehand about their enclosure type, temperature, humidity, etc.
- The Most Popular Scorpion Species Suitable As Pets.
- Emperor Scorpion – Detailed Guide: Care, Diet, and Breeding
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