These ants are farming insects (probably scale insects) for honeydew on a Ficus virens growing on the hill behind Fort Margherita in Kuching in December 2017.
Despite the large size of the Ficus virens fig tree we could only find one small group of farming ants on the tree.Growing next to the Ficus virens tree was a Ficus heteropleura fig tree with branches intertwined. This was a male tree with a few ripe male figs remaining on the tree. There were two species of ants associating with the male figs.
There were ants associating with the Ficus hetropleura as well. They appear to be drinking surface water from the leaf surface.