Portugal Travel

Scientists have discovered an astonishing supercolony of ants stretching almost 6000km (3700mi) from the Italian Riviera, through the south of France, along the Mediterranean coastline of Spain, across the length of Portugal and back out to Atlantic Spain. It is the largest cooperative unit ever recorded and consists of billions of Argentinian ants (Linepithema humile) from a species that was accidentally introduced into Europe some 80 years ago, probably on boats carrying imported plants.

Normally, ants from different nests don't get along but scientists suggest the initial success of this invading species led to higher than normal nest densities that favored cooperation over aggression. Now, even ants from opposite ends of the colony can recognize each other as genetically similar despite being from different queens.

The South American visitors are so rampant that they wiped out 90 percent of other ant species that live near them. Scientists also discovered a second large colony of Argentinian ants in Spain's Catalunya region, but when ants from these two supercolonies meet they invariably fight to the death.