Weaver ants are one of the most unique ants out there and follow a rather similar but unique way of living and they are what this article is all about, so without further ado, lets get right into it.
Weaver ants, fall under the genus “Oecophylla”,and are found solely within tropical and subtropical climates throughout Africa, Asia, and Australia. The ones found here in Australia are often known as “Green Ants” after their vibrant green color. What makes weaver ants so different from most other ants, is instead of burrowing down and forming their nests within the ground, weaver ants form their nests up in the trees. Their homes can usually be found towards the ends of branches, where the fresh, healthy leaves sprout. Fruit-bearing trees with broad leaves are favoured. But they’ll happily work within narrow-leaved eucalyptus trees… And sometimes will even utilize needle-thin leaves, like those from this beach she-oak.
Construction of Weaver Ants’ Nests
Construction begins with the ants firmly grabbing hold of a leaf with their mandibles, pulling, stretching, and curling them into position. Next, the ants do something quite remarkable. They enlist the help of an unlikely ally. Their own young. These small pill-shaped grubs are the ants’ larvae. They’re unable to travel on their own, so the ants carefully carry them over to their work site. At this point, the ants begin to gently tap their heads using their antennae. This induces the larvae to expel strands ofsilk from a small gland underneath their mouths. Normally, ant larvae use their silk for metamorphosis; spinning a cocoon which helps protect them as they develop into their pupal form, and eventually hatch as an adult. But in the case of weaver ants, they use their silken thread to instead weave leaves together.
Creating a super-strong binding. Once complete, the ants now have themselves comfy and safe, waterproof refuge. A perfect place to raise their young and allow their colony to thrive. Young colonies might have their nest comprised of just a single leaf curled in half and neatly stitched together. But as they expand their numbers, they gradually create additional nests. Established weaver ant colonies may occupy dozens at once, some with massive nests comprised of hundreds of leaves all clustered purposefully together. Usually nests a size of a volleyball/basketball are quite common. Other, much smaller nests, are often positioned along the perimeter of the colonies’ territory, acting as outposts. The first line of defence against intruders,the most common of which being foreign ant colonies, which may seek to ambush and invade their rivals.
This vanguard is often occupied by the eldestants of the colony, deemed to be the most expendable. But it’s not just raiders the weaver ants need to worryabout. Here in the dense foliage of the rainforest,plants are constantly competing with one another, reaching as high as they can to soak up asmuch light as possible. So naturally, down on the forest floor, not muchlight seeps through. Making ground temperatures significantly cooler. As ants are cold-blooded animals. When inhabiting cool climates, they aren’t nearly as active. Limiting their foraging capabilities and slowing down the growth of their future generations. This gives weaver ants a significant advantage over the forests’ ground dwelling ant species.
Living up in the canopy, weaver ants can stay nice and warm in the sun’s rays. Much like a crocodile basking on an open riverbank, the extra heat greatly extends the ants’ active hours and increases their productivity. But the canopy is ever-changing. Many trees lose the battle against neighboring trees which outgrow them, shrouding them in darkness. Some even become the target of parasitic plants, like strangler figure, which slowly wraps itself around its host, restricting the trees’ ability to grow, stealing their light from above, and absorbing up most of the surrounding nutrients within the soil below. So weaver ants must actively reposition themselves in order to pursue the sun’s valuable heat.
Successful Colonies Of Weaver Ants
The most successful colonies are often found nearby clearings in the forest, alongside rivers, and coastlines, and cyclone-affected areas where strong winds have torn down temporary clearings in the forest. Here, along the forests’ perimeters, they’re almost completely unhindered by shade. So the ants can take even better advantage of the sun’s warmth. Rapidly speeding up the development cycles of their young, helping them grow to enormous sizes. Some colonies can be home to hundreds of thousands of ants strong. The leaves which form their homes do inevitably die and crumble into pieces, and so, must be abandoned for fresh ones. So even in ideal conditions, weaver ants are kept extremely busy. Constantly rebuilding, renovating and relocating their homes. And all this hard work requires plenty of energy. Which weaver ants obtain from two main sources,honeydew and insects. Honeydew is sourced from sap-sucking invertebrates, like these mealybugs here. These tiny insects bore their way into fresh plant stems and leaves, and consume their sap.
As it’s digested, they excrete excess waste,in the form of a sugary liquid, rich in carbohydrates. Perfect fuel to keep the ever-busy weaverants, going. So instead of eating the bugs themselves,the weaver ants cluster around them. Waiting patiently for their sweet reward. But most other bugs aren’t so forward thinking. Ladybugs love devouring these little guys. The mealybugs can secrete a powdery wax, coatingtheir bodies, which helps discourage their attackers somewhat, but otherwise, they’revirtually defenceless. The ants are their real defence. As a few of them feed, many others patrol the surrounding area for threats. But there are some predators which can be a much trickier foe to deal with. Jumping spiders for instance. They’re often seen eyeing off their little friends.
On their own, they’re no match for the weaver ants. So they must be stealthy, and wait for the perfect opportunity to strike. If detected, the predator could easily turn into the prey. Weaver ants themselves, are very effective predators. They have excellent eyesight when compared to most other ants, and can utilize their strong, razor-sharp mandibles to great effect. Given the chance and they’ll tackle almost anything they can find. Once their prey is secure, Each ant pulls from multiple directions, stretching out and dismembering their helpless victims. So that they can be efficiently returned to their nests and distributed amongst their colony.
Diet Of Weaver Ants
A large part of weaver ants’ diet is other ants, a great source of amino acids. In the rainforest, ants are highly abundant and come in all manners of shapes and sizes. Many of the ground-dwelling species regularly venture up into the trees to forage food. But this often means passing through weaver ant territory. So they must be wary. All it takes is a single ant to notice theirpresence, and sound the alarm. Once one ant gets a good grip, all it needs to do is secure their rival down, and simply wait for reinforcements to arrive. This one on one scuffle is likely the victims only chance to escape. Several more quickly follow suit, pinning it down. It’s fate, now sealed. Not only are rival ants a nutritious and reliable source of food, but removing them, also reduces competition at the same time.
Any food that these ants would have discovered and returned back to their nest, now ends up as their own. Further proliferating their range and dominance. The more vast the colonies’ territories,the longer distances the ants must cover in order to best utilize the available resources and to maintain their control over it. In dense forests, weaver ants can easily navigatefrom one tree to the next, thanks to the vast labyrinth of vines and branches interconnecting the canopy. Allowing them to access and colonise multipletrees without ever needing to descend the long way down to the forest floor.
While most comfortable up in the trees, on occasion, they will venture to the ground to forage. Regularly Weaver ants also send out scouting parties . Scavenging upon whatever food they can get their hands on. The ants attempt to break apart whatever food they find even lizards into more manageable pieces, pulling from all angles. Some of the ants begin targeting the vulnerable joints, slicing into, and spraying them with formic acid. This noxious liquid, expelled from the ants’ abdomens, slowly burns and breaks down the flesh within.
Despite the ants’ determined biting andacid spraying, some food can be more difficult to cut then others obviously. Weaver ants have tiny hooked claws on the ends of their feet. Giving them incredible gripping strength,even at the steepest and most obscure of angles. Paired with their ability to work in synergy with their fellow colony members, they’re able to accomplish some pretty remarkable feats. Hauling up prey much larger than themselves,all the way up to the treetops. Sometimes weaver ants will improvise quicker routes along the way, to make their jobs a little easier. Some of which, at first, may not even seempossible… The path up a low hanging branch from the ground below.
The ants can’t jump or fly across like other insects might. Instead, they must build a bridge to close the gap. A bridge, made of ants. Each ant grips onto each other using theirmandibles, slowly forming a chain… And eventually, they link up from either end. And their shortcut is complete. Such incredible teamwork. But not all members of the colony are as capableat securing prey and traversing their environment as these ants are. Some rarely venture out from their homes atall. Weaver Ants are a “polymorphic” species. Meaning they produce different castes of workers,which perform distinct roles within their colony. The main caste are the “majors”. The ones who do most of the foraging and nestbuilding, and are the first line of defence against intruders. The other caste are the “minors”. They look almost identical to the majors, but side by side, you can see they’re much smaller in size. This caste of worker is assigned to nestingduties. Spending most of their time tending to thecolonies’ developing brood, and looking after their queen.
The mother to the entire colony. Quite the accomplishment. So that’s weaver ants. They’re such an incredibly unique ant species. From the way they construct their homes from leaves, using their own young as tools… To building living bridges to efficiently scale their surroundings… To their brutal yet methodical approach of securing prey. I think what amazes me most, is their extreme aggression. Just slightly brushing against their nests or a nearby branch is enough to set them into a frenzy. As a defensive response, they posture up their bodies, and curl their abdomens over their heads. Poised to fire out rappid strings of their formic acid. If this liquid were to get into a potential that’s eyes, like a bird or a lizard, it’d surely make for a great deterrent. One of the reasons most other animals liketo give these guys a wide berth.
Next to meat ants, they’re probably the moster territorial ants out there. Regardless, I really enjoyed documenting these guys, and exploring the forests which they, and countless other animals, call home. Like giant butterflies and grasshoppers, thesize of our hand. Plenty of other amazing ant species, liketrap-jaw ants… Jumping ants… Spider ants… Golden-tailed spiny ants… And lots more.
The cute little turtles swimming up and down the streams. And the massive saltwater crocodiles hanging out along the estuaries, the largest living reptiles in the world. I was even lucky enough to spot 3 wild southerncassowaries, one of the largest birds in the world. These modern-day dinosaurs mostly feed onfallen fruits and are highly important seed dispersers. Many of the forests’ plants depend entirelyon these birds to survive. Unfortunately, they’re an endangered species. Mostly due to habitat loss as a result of deforestation. Let’s just hope these ancient, and incredibly biodiverse forests are around for a long time to come. Sadly, Australia has just been hit with oneof its worst bushfire seasons in recorded history, which definitely doesn’t help. I’m fortunate to have not been affected by thefires, living here in Melbourne. Aside from experiencing several days of thicksmoke. I could only imagine what it was like closerto the flames.
Whilst fire is a natural part of the Australian landscape, with some forests actually needing fire in order to reproduce and thrive, these fires, following Australia’s 2019 record high average temperatures, and low levels of rainfall,burned at unprecedented strength. Devastating vast amounts of land and claiming the lives of countless native animals. Many which managed to escape the flames had little to no habitat left to them, and ended up either starving or being hunted down by invasive predators, like feral cats and foxes, which have an easy time spotting them within the open, scorched land. The combination of this extreme heat and prolonged droughts, also allowed fire to reach its way into environments which are not naturally adapted to it, unable to fully recover if affected.
Even lush rainforests which have stood since the cretaceous period, at least 65 million years ago, were ablaze. As earth’s climate changes we can expect to see extreme natural disasters like these occurring more and more frequently, and on even larger scales. Governments, and policies, at least here in Australia, rarely treat environmental concerns seriously. Repeatedly dismissing scientific researchand delaying the transition from fossil fuels into cleaner energy production. So it’s really up to us, as individuals,to take matters into our own hands.
Hopefully, this article was informative, and gave you some interesting insight about Weaver ants as well as their unqiueness when it comes to insects. If you have any further related questions feel free to use the comment section below. Moreover, if you want to know an answer to whether insects seek and take revenge, we have a great article written on just that, you can give that a look “here“. And if you want to go through some interesting facts about insects, natgeokids has a great article written on that, you can give that a look “here“