Dinomyrmex gigas
This species was previously named Camponotus gigas, but in 2016 a detailed scientific study concluded it was not a Camponotus but had its own distinct lineage, and it was then renamed Dinomyrmex gigas. This is now the correct recognized scientific name for this ant.
This is a stunning species. Its claim to fame is that it is one of the largest ant species in existence. The normal workers measure 10-20 mm and the larger major caste up to 28 mm. The queens are a massive 30-35 mm in size.
The queens have a jet-black thorax/head and a beautiful golden/bronze abdomen with black bands. The workers are similarly colored but have an all-over golden-orange abdomen. They have long antennae and legs and their antennae continually wave around absorbing the pheromone signals in the air.
Distribution
This species is found in undisturbed natural rainforests in Southeast Asia. It has been recorded in Borneo, Malaysia, Sumatra, Singapore, and southern Thailand.
Their normal habitat is humid dense jungle and due to its location near the equator, the temperature is quite steady throughout the year with little variation during the different seasons. If you research the weather stations in the locations they can be found, you will be able to see the yearly weather records for minimum and maximum temperatures, along with the rainfall and humidity.
Colony size
Mature Colonies are reported to have about 5000–7000 workers, distributed among several satellite nests. The average number of nests in a mature colony is reported to be between 7-12 with the largest central nest containing the colony’s single queen.
These nests are most often found in the soil between the buttress roots of old mature trees and in the hollows of fallen or decaying tree trunks. The separate satellite nests are usually 10-20 meters apart. Having several different nests spread around their foraging area enables the quick recruitment of workers when a nearby food source is found.
Although colonies expand slowly compared to many other species, this ant is the dominant pinnacle member of the South-East-Asian tropical rainforests ant community.
Mature colonies are recorded to consist of 87% workers and 13% majors. The workers on average weigh 135 mg and the majors weigh up to 372 mg. In comparison, the workers of most common ant species weigh between 5-10 mg.
Food
They forage mainly at night and at dusk large numbers of workers leave their nests to look for food. They forage in huge three-dimensional territories up and over the rainforest canopies. During the hours of darkness, long lines of workers can be seen following trails up trees/vines into the forest canopy and returning full of food. During the daytime, foraging is reduced and is restricted to a much smaller number of workers who tend to roam over the forest floor.
The ant is a very effective forager, utilizing both efficient communication and recruitment. Honeydew/exclusions from sap-sucking insects make up 90% of their diet, and at night it climbs trees and bushes to milk these sap suckers, but they will also consume any dead insects that they find and bird droppings.
Territorial defense
The very large major caste’s primary role is to defend the nest and protect the foragers. They have large heart-shaped heads and strong mandibles. These are rarely involved in foraging but perform colony border patrol and have a strong bite that can cut human skin.
The majors conduct patrols along foraging trails to defend their territory from invaders such as predatory insects and other ants. These patrols normally occur throughout the night while the foraging trail is active, with the majors retreating to their nest in the morning. They defend key points important for food or access to the canopy, usually in a group of 3 to 4. These major workers will stand guard throughout the night instantly attacking anything that threatens their food supplies.
Due to its large foraging range, it is inevitable that these giant forest ants have to deal with threats from other ant species and other colonies of their own species. In defending its territory from other species of ants, the giant forest ants will fight vigorously spraying acid and instantly attacking any threats. This often leads to death from both sides. However, in dealing with other colonies of their own species, the major workers of each colony engage in ritualistic one-to-one battles. These battles can rage on for as many as 30 days in what is known as an ‘ant war’ but rarely result in the death of either party. Only the majors are involved in these battles.
Each battle between one pair of ants always followed a regular pattern of behavior starting with the meeting of both aggressor and the defending sentry. Occasionally, the aggressor will drum the ground with its gaster producing an audible sound, before both parties open their mandibles and raise their first pair of legs. Once the aggressor touches the defender, the fighting begins. Intense antennae waving and vibrating gasters occur throughout the fight. Both ants also raise their body with open mandibles to threaten each other. ‘Front leg boxing’ then occurs with the continuous sweeping of front legs alternatively up and down. Very often, the fight is decided at this stage, with the ant that held its leg up longer becoming the winner of the ‘round’ and the loser retreating. However, occasionally the fight progresses into mandible grabbing with each ant trying to grab and drag the other ant onto the ground in a tug-of-war. A single win however does not stop the confrontation, with the majors taking a break by retreating to their territories and grooming their antennae and legs before returning to the tournament site to fight again. The fight continues throughout the night, with tired majors substituted and the ritualistic fighting continuing.
Captive cultivation
Previously there have only been newly mated queens offered for sale. Newly mated queens are very difficult to find in the wild and many queens being offered for sale are not fertilized. This is because the high price tempts the collectors to take the much easier and more profitable option - and simply collect female alates from large mature colonies, remove their wings, and then deceptively sell them as newly mated queens.
We purchased small numbers of ‘new queens’ from several different sellers in late 2022, only to find that many showed the symptoms of being unmated and subsequently failed to establish colonies and died. From this personal experience, a good estimate is that 50-60% of the queens offered for sale are probably infertile. We purchased queens from six different sellers/hobbyists and only two sellers turned out to have supplied true fertile queens. Notable here is that all the queens we purchased from two sellers in Malaysia turned out to be infertile.
Another problem is that new queens can be parasitized while out of their nests by a ‘phorid fly’ whose larvae will consume the queen’s internal organs resulting in her death a few weeks after flying. No symptoms are visible until she drops dead! These flies will lay eggs in any wound on the queen’s body even the smallest of scratches or scrapes and when the eggs hatch the fly larvae will burrow into the queen and consume the queen’s tissues.
Signs that the queens are not fertilized are that they will frequently try and escape their captive enclosure with the urge to want to mate. When they cannot escape, they will sometimes lay eggs, but only a small number, and although they seem to care for them at first, they rarely allow them to emerge into larvae continually eating them.
Another major problem with stock sold by most sellers is that the queens they are selling have been collected by their suppliers many weeks previously. The queens of this species will eat their eggs if disturbed - which then happens when they are packaged and posted to customers. As with many species during the colony foundation stage, the true fertilized queens have an initial spurt of laying soon after their flights, and will not lay again due to an inbuilt foundation strategy and limited energy reserves. Hence when sent to customers in the post they will eat any eggs they have already laid and frequently not lay again, or if they do will only lay a very small number, and they will then have to start the establishment stage again after having already exhausted much of their food reserves.
Buying just a queen is a high risk both because of this built-in egg-laying habit, the possibility of the queen being parasitized, and most importantly because there is no way to confirm the queen is fertilized.
Even if you can obtain a true fertilized queen getting them to establish a colony is very difficult, and even if the environmental conditions are ideal, they will eat their brood at the slightest disturbance. This species has proven to be the most difficult we have cultivated to the establishment phase.
Because of these problems, we will not sell just queens on their own, only young colonies - as then it is confirmed the queens are fertile, and they already have some workers to care for the queen and brood. However, due to the time and care it takes to raise these - they are priced accordingly.
It takes just over two months for the first workers to emerge. From the records we have been taking the average time for the first worker to appear from when the first eggs are laid is 62-65 days, and it is a further 2-3 weeks before all the initial brood have emerged. Nearly three months of careful care just to raise the first primary brood. The next batch of workers to emerge will take another 2-3 months to appear - so the larger colonies we are offering have been carefully nurtured for around six months.
Natural Colony establishment - from personal observations
After their swarm flights, the newly fertilized queen will look for a suitable place to start her colony. This search to find an ideal location often takes several days. During this time, she will hide inactive amongst leaf litter during the day, then at night she will wake up and explore the forest habitat. The queens usually prefer to start their colonies in the ground amongst a mass of tangled tree roots or in rotten wood. Although it often takes a few days to find a suitable place - as soon as she is contented, she will dig out a large foundation chamber and then completely seal herself in. The queens of this species are fully-claustral and do not require any type of sustenance during colony foundation. Offering them food creates disturbance and will frequently result in them aborting/eating their brood.
Once the queen settles down within 2-3 days, she will start to lay her first eggs, and within about ten days she will have 15-25 eggs, and then she will stop laying. It takes about 25-28 days for these eggs to hatch into larvae, during which time she continually moves them around and meticulously cleans them.
The larvae mature quickly and they will increase in size by 1 mm a day. In good conditions, they will mature and spin cocoons in 12-15 days. Some of the initial eggs will be eaten by the queen and others fed to the young larvae, resulting in an average of 5-8 cocoons from the initial batch of eggs she laid.
At this stage, it seems normal for the queens to consume the contents of 1-2 cocoons to keep themselves alive and to provide nourishment for any remaining larvae that have not yet pupated. The queen now having been released from the demands of feeding the larvae and having obtained some nutrition from eating the contents of a few cocoons, will start to lay a second follow-on batch of eggs.
The first workers emerge from the cocoons after 22-28 days. These take a few days to harden up then take over the care of the brood and attend to the queen. Some researchers state that they break out of the foundation chamber urgently looking for food. However, from our own observations, in all the colonies we raised the time taken before they opened up an entrance into the foraging area was similar, and the first workers did not leave the foundation chamber until 12-14 days after emergence. In the wild, this is a critical time as predators such as geckos, spiders, or hunting wasps could decimate the early workers, leaving the colony without workers at a time when finding food is essential to the colony’s survival.
During the establishment stage, the queen does not leave her foundation chamber and goes without any food at all living on her body reserves. From when the queens fly to when their first workers start to forage is nearly 3 months. For the colonies, we raised we took careful records about the time from when the queen left her initial mother colony to when her first workers took food back to her, and it was between 82-85 days.
More information
As with many species the first workers are smaller than normal, as it is a priority to raise a workforce as quickly as possible and get new workers out to forage to keep the queen alive. The first workers whom we like to call ‘minim workers’ measure about 10-12 mm and their life expectancy is shorter than normal-sized workers. The emergence of these minim workers does not signal the establishment of a colony as their life expectancy is only a few months, and in that time, they must complete raising the follow-on brood which will emerge as normal-size workers. If the weather is bad there is a possibility that they will have limited foraging opportunities, and if food is scarce, they may not be able to raise the next brood before they die.
The workers that emerge from the second batch of eggs laid, which the minim workers have fed and cared for, are normal size and notably larger than the minim workers. These have a much longer life expectancy and once the queen has several of these normal-sized workers to care for her and the brood, the colony’s survival prospects are much better.
Keeping in captivity
Display
The foraging area is very important when keeping this species. In the wild, the colonies roam over vast areas and a single large mature colony can forage over an area the size of a football pitch. And remember this is 3-dimensional foraging not over a flat area.
Keeping them in a small plastic nest with a small bare foraging area will result in colony apathy and they will stop breeding and can be likened to keeping a tiger in a dog cage. They will however respond well in a good sized naturally landscaped arrangement. Natural setups will also let you observe some of their other behavioral aspects which are often not seen - such as their ability to jump!
These would make a stunning central display feature for a large room, housed in a glass tank/aquarium that is landscaped to imitate a natural lowland forest.
A thin layer (2-3 cm) of peat-based compost can be used as a base medium, this has the benefit of holding moisture which it slowly releases into the air helping maintain a good humidity level. The tank should be landscaped with a network of wood branches positioned to simulate a canopy walkway, and potted plants to imitate a natural forest. Plants such as ferns, small climbers, moss and maybe even some orchids would look particularly impressive. The tops of the potted plants can be covered with large gravel/bark chips to stop the ants from digging into the pots. A plastic dish sunk into the compost filled with sphagnum moss will provide a source of water for the colony. You can use an artificial nest for the colony that is positioned inside the tank and rests against the glass, allowing you to view the chambers. A small water atomizer will produce a misty forest appearance and help keep the humidity high, and a red/orange night light can be used to illuminate the tank at night. The misters and lights can be controlled by a simple 24-hour plug-in time controller which can be set to imitate the natural day length where they occur in the wild.
For young colonies, a regular-sized 90x45x45 cm aquarium will suffice for a few months, but as the colony increases in size, a larger size should be considered.
Such a display would be the focal point of any room, showing a natural misty tropical forest habitat, illuminated at night to simulate moonlight, and allowing you to observe these giant ants in their natural habitat.
You can see several landscaped tank designs in the photographs. These will give you an idea of the kind of landscaped arrangement you could use to house this species.
Temperature/humidity:
You should try and imitate the same conditions that are found in the habitats where this species naturally occurs. To do this you can refer to the weather station reports for locations where they can be found. An example is given here for Penang in Malaysia where I have personally seen colonies in the wild. These weather station reports will show you the average monthly low and high temperatures, amount of rain, daylight hours, humidity etc.
https://www.timeanddate.com/weather/malaysia/penang/climate
Food
Some of the food we have been giving our colonies include sugar water, honey, jam, other ant’s brood, bird droppings (moistened), ripe fruit, cat food, and dead insects. You can try other various food offerings but remember it is advisable to remove/replace any food not consumed after 48 hours to stop molds from forming. To simulate their natural habit food dishes and feed tubes should be placed above the ground, supported somewhere amongst the branches.
Guaranteed fertile queens
As the colonies we are selling are headed by queens that have already raised their first workers we can obviously state without doubt that they are guaranteed to be fertile.
When you check out this species for sale elsewhere a few sellers list just queens for sale but they never seem to be available, suggesting the offering is a ‘false flag’ as such, and those that do/have actually stocked them do not offer any form of guarantee that the queens offered are actually fertile. One vendor even states ‘not guaranteed to be fertile!’ (Ask and we will send you the link.) One does wonder who is willing to take the risk and pay several hundred pounds for a queen that is not even guaranteed to be fertile!
The colonies we are offering are headed by strong healthy new queens that were collected in October/November/December 2022. We have two sizes available: those with their first batch of founding workers which will number between 5-7 workers, and more advanced colonies that will have 12-15 workers.
If you decide to purchase this exciting species, please ensure you have the nest/habitat area set up and temperature/humidity fully tested for a few weeks prior to delivery. Everything should be stabilized so that when the colony arrives it can simply be placed into the allocated habitat, and left to settle down without any additional disturbance.
Purchase requirements
These are exclusive to our shop and no other sellers can offer true young colonies of this species.
# This species is only recommended for hobbyists that have good knowledge/experience in keeping exotic ants.
# Due to the price and expert care required, we are restricting sales to hobbyists over 21 years of age.
# Orders from previous customers held in good standing will take priority over new unknown customers.
# No wholesale offers will be accepted.
# Sales are restricted to one colony per customer.
# We will require a ‘purchase indemnity form’ to be signed prior to accepting an order.
The 'terms of purchase' will be sent to you upon request.