Deag writes "A mega colony of one family of ants has spread all over the world. Previous mega colonies in California, Europe and Japan have been shown to be in fact one global colony. Ants from the smaller super-colonies were always aggressive to one another. So ants from the west coast of Japan fought their rivals from Kobe, while ants from the European super-colony didn't get on with those from the Iberian colony. But whenever ants from the main European and Californian super-colonies and those from the largest colony in Japan came into contact, they acted as if they were old friends."