Tiny Fire Ants Invade Israel, Causing Painful Stings and Bizarre Self-Cloning

The arrival of the small fire ant in Israel over two decades ago has introduced a painful nuisance to humans and animals, alongside a biological marvel that challenges conventional understanding of reproduction. Dr. Eyal Privman from the University of Haifa's Evolution Institute explained that these ants, believed to have arrived via maritime trade from South America, likely entered the country in shipments of wood. Their painful stings, which can feel like burning due to multiple ants attacking simultaneously, are caused by a venom-injecting stinger, similar to bees and wasps, capable of piercing human skin. While not typically causing life-threatening allergic reactions like their larger counterparts, the small fire ant's presence is a significant discomfort.

Despite originating from tropical, humid regions, the small fire ant thrives in Israel's arid climate due to human irrigation of fields, lawns, and gardens, which creates the necessary moisture. Unlike most ant species with a single queen, small fire ant colonies can host numerous queens, enabling rapid reproduction and egg-laying. Colonies expand not by queens starting anew, but by groups of queens and workers migrating short distances to establish new nests. Humans facilitate long-distance spread, primarily through the nursery trade, where infested plant pots introduce ants to new areas.

Global warming could potentially expand the ants' habitat by making previously cooler regions more hospitable. However, water availability remains a critical factor in Israel; increased drought due to climate change could harm them without continued human irrigation. The most astonishing characteristic of the small fire ant is its reproductive strategy. While worker ants are produced through normal sexual reproduction, queens clone themselves, creating genetically identical offspring. Males, however, are clones of their fathers, with the mother's DNA being removed from the egg and only the father's DNA remaining. Researchers are still working to understand the precise physiological mechanisms controlling these reproductive processes, particularly how a queen determines whether an egg will develop into a cloned male, a cloned queen, or a worker ant.