The weaver ant (Oecophylla smaragdina) is a type of red ant, often mistaken as fire ant. In Malay, it's called semut api or kerengga (which translates to fire ants, hence the confusion). They make trees in leafy plants by stitching together nests using the silk produced by their larvae.
We find quite a lot of these ants in our garden especially during rainy season. The other day day, we found a whole bunch of them on our sui mei bonsai plant (Wrightia religiosa). Sui Mei has very fragrant and dainty white flowers, and the plant in general requires quite little maintenance and flowers all year round. We just have to give it a trim now and again to keep it nice and tidy.
Weaver ant on a sui mei flower
Don't get too close! I bite.