Nature Notebook – Ant Battles

The driveway edge seemed to have a moving brown puddle. The mysterious “puddle” was an ant battleground. Ant wars are a relatively common occurrence but seldom noticed by people.

Each ant colony, even those of the same species, has a unique scent that is bestowed upon them by a healthy queen. Patrolling workers mark their territory boundaries with this smell. Whenever an ant meets another, it commences the “antenna greet.” The touching antennae sense each ant’s colony scent. If the scents match, life goes on. If they don’t, and it’s just an errant forager from another colony, they each do a quick u-turn.

Occasionally a colony needs to expand its territory because they need the space or the resources. When ants from one colony move into another’s territory, they encounter the defense patrol. When these ants detect the foreign scent they release a “fight” pheromone. The nestmates pour out and engage the intruders in a battle to the death. Eventually one colony stops when their numbers are low and the war is over.