I will try to keep this simple. Out among the leaves and rotten logs of North America lives the Asian needle ant (Pachycondyla chinensis). This ant is native to Japan1. It was first recorded in the U.S. in North Carolina, my state, where it was largely ignored and described as being innocuous. That was a mistake; it was not.
Work by Benoit Guenard, Eleanor Rice (AKA, Dr. Eleanor) and others including Pat Zungoli and colleagues at Clemson University has revealed this ant to now be among the most common ant species in large parts of North Carolina and South Carolina. Where it is abundant, it takes over. Native ants become rare. Seed dispersal of some native plants slows. It is a bad, bad ant — though because it is alive it is, like all species, also fascinating and mysterious.