Ant Mill Death Spiral

Army ants trapped in a circular pheromone loop — a tragedy of collective intelligence

Army ants (Eciton) navigate by pheromone gradients. Isolated from the colony, they follow the strongest trail — each other. This creates a positive feedback loop: a rotating mill where thousands of ants circle until exhaustion. Observed in nature; the largest recorded mills are over 370m in circumference (Schneirla, 1944). High pheromone decay disrupts the mill; low decay makes it self-reinforcing.