There’s not a lot of information on this ant save that it’s from Southeast Asia, but one paper on it (reference below; free access) examines the microstructure of the hairs (and notes that the biology of this species and its relatives is almost completely uknown). What do the hairs do? The authors say that they convey mechanical stimuli to the ant and protect it from being nommed:
We suppose that the whole hair cover may serve as a shield against attacks of other arthropods, especially ants, which are highly common in the habitat of E. melanarctos. The sensory apparatus of the hairs gives exact information about contacts with the surroundings. The lipophilic secretions of the pedestal glands possibly function as lubricants that keep the non-living hair shafts intact, i.e. elastic and waterproof-like sebaceous glands or rump glands in mammals and birds, respectively.
Here’s a scanning-electron microscopic photo of the hairs, which arise from “pedestals” on the cuticle:
Gnatzy, W. and U. Maschwitz. 2006. Pedestal hairs of the ant Echinopla melanarctos (Hymenoptera; Formicidae): morphology and functional aspects. Zoomorphology 125: 57-68.