The Work Ethics of Weaver Ants

The Work Ethics of Weaver Ants

As we walked from the ACCC to the canal, we saw that people from the nearby villages would often walk there with their animals and wash their clothes. On both sides of the roads and in the canal, we saw a lot of invasive plants. Prosopis juliflora, Nila grass (Mimosa diplotricha), Mikania (Mikania micrantha), Lantana (Lantana camara), Parthenium, Calotropis procera, Chromolaena, etc. are some of the more common species. There are also several red weaver ant (Oecophylla smaragdina) nests near the ACCC. One day, we set out toward the canal because we assumed that red weaver ant nests would be located there, but surprisingly, we saw only a handful of nests after walking so far. Therefore, we questioned some farmers there about the ant nests and inquired about the types of pest control they apply in their fields. It was a once-in-a-lifetime experience getting lost in a paddy field and having to find our way back to ACCC in search of an ants' nest. However, it was interesting to note that ants' nests were found on one side of ACCC, despite the fact that the area was an organic cashew farm, while the other side, along the canal, had none.

Even though our team has taken close-up pictures of their nests, we wanted to watch these brilliant insects build their nests and take pictures of each step. After sneaking up on a few nests and getting bitten by the workers, we were finally able to get a good look at this kind of nest-building activity on Neem and Prosopis.

Weaver ants make nests by weaving leaves together with larval silk. Colonies can include more than a hundred nests over several trees and more than 500,000 workers. Their capacity to create large nests from live leaves has led to their ecological success. Luckily, we were able to witness the beginning stage of the nest-building process as well as the few empty nests. Workers look for possible nesting leaves by pulling on the edges of the leaves with their teeth. When a few ants have managed to fold a leaf in on itself or pull one edge toward another, other ants nearby join in. Higher group sizes boost the probability of workers joining a concerted effort.

Once the edges of the leaves are drawn together, other workers use their beaks to get larvae from existing nests. These workers hold and manage the larvae in a way that induces them to secrete silk by letting them produce more silk. The workers then move between the leaves in a highly coordinated way to tie them together.

The nests of weaver ants are usually elliptical in shape and can be as small as a single small leaf folded and tied to itself or as big as a half-meter-long nest made of many leaves. The time it takes to build a nest depends on the type of leaf and the size of the finished nest, but a large nest can often be made in much less than 24 hours. Even though weaver ant nests are strong and can't let water in, workers in large colonies are always building new nests to replace old nests that are dying or have been damaged by tree cutting. Since they were disturbed by tree cutting and are moving to different tree branches with their larvae, we also witness their severe aggressive behaviors. After getting bitten by a few of the worker ants for getting too close to their nest construction, we decided to stop photographing and just observe them from a distance while admiring the excellent teamwork. The time it took them to complete the meticulous stitching was well over a day. Every time I go further into the ant colonies, I learn something new about their behavior.