Asian Weaver Ant

Workers are entirely orange-red and measure roughly 5–10 mm, split into two worker castes: smaller minor workers that tend the brood inside the nest, and larger major workers with stronger legs and mandibles built for foraging and nest expansion. Queens are much larger (20–25 mm) and greenish-brown in color — the source of the species name smaragdina, Latin for "emerald."

Weaver ants range widely across tropical Asia into northern Australia — from India through Southeast Asia, Indonesia, and the Philippines, to Queensland. In Thailand they occur nationwide, thanks to how adaptable they are. Unlike most ants, they don't nest underground at all; they live entirely in trees (arboreal), most commonly in orchards, secondary forest, and farmland with large-canopy trees such as mango, cashew, coconut, and citrus — species with leaves large and tough enough to weave into a nest. A single colony rarely occupies just one nest; it typically spreads across many satellite nests on branches throughout one tree, or across several neighboring trees.

The real challenge with this species isn't diet or temperature — it's space and temperament. Major workers bite hard and can spray acid, so care is needed when opening or relocating a nest. The colony size figure listed on this page (around 50,000) refers to a typical, commonly seen single-nest colony, not a record maximum — weaver ants are unusual in that one colony can expand into many nests spread across multiple trees at once, and the combined population of that whole network can reach into the hundreds of thousands in the wild. That's an extreme case, though, not what a keeper should expect to see.

Good to Know

Humans have used weaver ants for thousands of years. Ancient Chinese farmers used them to control pests in citrus orchards as early as around 304 CE, making it one of the oldest documented forms of biological pest control in the world. The same principle is still used today in mango, cashew, and cocoa farming across the tropics. In Thailand, the species is best known for its eggs, a key ingredient in dishes like yam kai mod daeng and gaeng kai mod daeng in Isaan cuisine.

Weaver ants are highly territorial and more aggressive than most ants — workers bite and spray formic acid at anything they perceive as a threat almost instantly. Nest-building happens at night: workers form living chains, pulling the edges of two leaves together, then relay silk-producing larvae along the seam like a shuttle, using them to stitch the leaves shut. It's considered one of the most complex examples of cooperative construction in the ant world.

Before deciding to keep this species, know that weaver ants need vertical space and live branches or plants to weave their nest on — not the acrylic formicariums most keepers are used to. Ideal temperature runs around 26–32°C with fairly high humidity, 70–90%, reflecting their native humid tropical forest habitat. For food, they take both insect protein (crickets, mealworms, flies) and sugars from diluted honey or aphid honeydew, much like most other ant species.