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. If you put out good for it, delicacies like dead roaches, it does not lay trail pheromones to them. Instead the worker who finds the food runs back to her nest, picks up a sister and drags that sister to the food, “HERE it is, thump.”
All of this is known if not well appreciated. Also known is that this ant stings. It stings hard enough to make brave graduate students wince and less brave graduate students switch to working on fruit flies. Many folks appear to be allergic to these stings—the risk of anaphylactic shock from stings by the Asian needle ant is much higher than from stings of, say, honeybees. Fortunately, the Asian needle ant is mostly peaceful. On its six, long legs it walks softly but carries a big sting.