Weaver ants on the march up a tree trunk
In Lombok, a column of ants was moving up a tree trunk, threading between patches of green foliage, each ant following the one ahead with the single-minded focus ants are famous for. They were light brown, small but sturdy, with long antennae flicking constantly, and they were clearly on a mission. I followed the column with my lens, wondering where they were headed.
These are Oecophylla smaragdina, the Asian weaver ant, a member of the family Formicidae in the order Hymenoptera. The species name smaragdina means emerald green, which describes the vivid green of the workers in many populations, a colour that can make whole colonies look like part of the canopy. In Lombok these are the dominant ants of the trees, and their nests are the most striking thing about them: living balls of leaves, stitched together with silk.
Weaver ants build their nests by pulling living leaves together and binding them with silk produced by their own larvae, which the adult workers carry back and forth like living glue guns. A single colony can span several trees and hold hundreds of thousands of workers. They are also ferocious defenders of their territory, and their bite, aided by a spray of formic acid, is a memorable experience for anything that disturbs them, including careless photographers.
Watching the column march up that trunk, I felt like I was watching a small nation on the move. Weaver ants do not just live in the trees; they run them, and everything else in the canopy knows it.
