Ants Use Chemical Weapons

Credit: Trevor Sorrells

I guess ants don't have a Geneva Convention.

ScienceDaily (June 7, 2011) — Stanford sophomores studying ants in a summer course discovered that the local ants were using poison to kill invading Argentine ants. The discovery provides new insight into the war between the local "winter ants" and the South American invaders who have shown up everywhere from California to South Africa.

Argentine ants are taking over the world -- or at least the nice temperate parts. They've spread into Mediterranean and subtropical climates across the globe in sugar shipments from Argentina, and no native ant species has been known to withstand their onslaught -- until now. A group of Stanford University undergraduate students working on a class project have discovered that a native species, the plucky winter ant, has been using chemical warfare to combat the Argentine tide.

The winter ants -- named for their unusual ability to function in cold weather, rather than grind to a halt like most insects -- manufacture a poison in a gland in their abdomen that they dispense when under extreme duress. One tiny drop applied to an Argentine ant is enough to put an end to it. In laboratory testing, the poison had a 79 percent kill rate.