The Argentine ant is a well-known invader of urban and agricultural ecosystems, particularly in certain regions of the world with Mediterranean climates. This statement is half-true: the pervasive ant is very well-known in these areas; but, biologists aside, few people realize that it's an invasive species, only introduced to Europe in the 1920's and to the United States around 1890. Yet, in this brief time, the Argentine ant has established two massive supercolonies along the coast of the Iberian Peninsula and one throughout California, where it has driven out all native ant species that it comes across.
The largest of the supercolonies stretches over 6,000 kilometers from northern Italy westward, around Spain and Portugal, before reaching back into Spain – nearly the territory of the Roman Empire after the Punic Wars. If we take seriously the idea that individual ant acts more as a tissue than an organism, then this supercolony is in fact a superorganism, potentially the world's largest living thing. What are the mechanisms that make the Argentine ant so successful? How do these mechanisms help to determine membership within a supercolony? How do we make the leap from supercolony to superorganism? And what is a superorganism?
