An ant mill is an observed phenomenon in which a group of army ants, separated from the main foraging party, lose the pheromone track and begin to follow one another, forming a continuously rotating circle.
This circle is commonly known as a “death spiral” because the ants eventually die of exhaustion.
The phenomenon is a side effect of the self-organizing structure of ant colonies. Each ant merely follows the ant in front of it, which functions until a slight deviation begins to occur, typically by an environmental trigger, and an ant mill forms.
An ant mill was first described in 1921 by the American naturalist William Beebe who sighted it in a jungle in Guyana .
The circle he saw was 1,200 feet in circumference, and it took each ant two and a half hours to complete the loop. The ants went around and around the
circle for two days until most of them dropped dead.
Similar phenomena have been noted in caterpillars and fish.
As Steven Johnson showed in his illuminating book ‘Emergence: The Connected Lives of Ants, Brains, Cities, and Software’ , an ant colony normally works remarkably well. Each individual ant knows, on its own, almost nothing. Yet the colony successfully finds food,gets all its work done, and reproduces itself.
But the simple tools that make ants so successful are also responsible for the demise of the ants who get trapped in the circular mill. Every move an ant
makes depends on what its fellow ants do, and an ant cannot act independently, which would help break the march to death.
Independence needs relative freedom from the influence of others.
To think on our own.
To not march to death in a circle just because the ants in front of us are doing so.
Independence is important to intelligent decision making. It prevents aggregation of the mistakes that people make.
Errors in individual judgment should not become additive.
Systemic bias emerges because one depends on the one ahead for information.
The ants need NEW information rather than the same old info everyone is already familiar with.