It is an invasive species with no native predators, so they're pretty much running amok.
The NYTimes article goes on to say:Variants of the species found in Colombia have been known to asphyxiate chickens and even attack cattle by swarming over their eyes, nasal passages and hooves, according to the Center for Urban and Structural Entomology at Texas A&M, which is conducting much of the research on the ants.
The ants often eat fire ants, with which they are sometimes compared, and they “outcompeteâ€