In Southern California, five rival supercolonies of Argentine ants are engaged in a war that has led to 15 million deaths already

Millions have died when humans went to war against each other ever since the dawn of humanity. While animals are known to have their own rivalries and great wars, one among ants, and at such intensity, is a first. In San Diego, a violent war between five rival ant supercolonies has been raging for decades, killing millions upon millions of them annually, as per a report by IFL Science.Argentine ants: All over the worldThe ants in question are Argentine ants, native to South America. The species (Linepithema humile) is highly territorial and prone to aggression towards other insects, using their antennae and chemical signalling to identify whether others are an outside foe or related friend.Throughout the 19th century, the species was accidentally spread across the world through trans-Atlantic shipping. Ants would hitch a ride on some cargo in South America, then find themselves planted across the world, from Europe to Japan. These different parts of the world were seeded by a small number of ants and their population was much less genetically diverse. They all "smelt" the same to each other, and thus nests treated each other as kin.As they stopped fighting and killing each other, m...