Marching in Formation

I crouched low beside a sunny stone paver in the courtyard, watching a neat line of tiny black garden ants march in single file. Their column moved with remarkable discipline, each carrying a pale fleck of breadcrumb across the seam. Curious to test their coordination, I picked up a dry pine needle and laid it gently across their path like a miniature timber bridge. The vanguard halted, tapped the slender pine shaft with deliberate antennae, and calmly steered around the tip. Within seconds, the entire rank adjusted its bearing and reformed the straight line without a single misstep. A thoroughly impressive display of field navigation.