Study Finds Ants Turning Enemies Into Allies After War

Posted on March 25, 2016

Acacia ants battle

Ant colonies often engage in fierce battles against rival colonies. University of Florida researcher Kathleen Rudolph has found that at least with one ant species members of the surviving losing ants get incorporated into the new colony.

Rudolph studied acacia ants, Crematogaster mimosae, in Africa which are known for having a fearsome bite. The ants inhabit acacia trees and protect them. The ants bite defends host trees against even large animals like elephants and giraffes. Ants are also aggressive toward each other and will fight to the death to defend their territory.

A large battle could leave the victorious colony trying to defend their newly expanded territory with a workforce heavily depleted from the war. In a new study, Rudolph and UF postdoctoral research associate Jay McEntee found that victorious colonies recruit members of the losing colonies to help.

The researchers conducted ant war experiments at the Mpala Research Centre in Kenya. The researchers tying unrelated ant colonies' trees together and the counted the result ant casualties in tarps placed below the trees. The researchers analyzed the DNA of hundreds of the ants and found that the battles change the genetic make-up of victorious colonies.

The researchers found that members of the losing colony can become part of the winning colony and help defend its residents and territory. They also found that some cases did not produce a winner. Some battles result in colony fusion. The warring colonies ceased fighting and fused together with the queen from each colony still alive.

Rudolph says in a statement, "Colonies are battling so aggressively that many individuals die, but then they are able to just stop fighting and form a lasting truce. It's pretty remarkable."

A research paper on the study was published here in the journal, Behavioral Ecology.

Photo: Aileen Mack/The National Geographic Society