From vibrations alone, acacia ants can tell nibbles from the wind

Researchers find that the ants of the acacia tree are tipped off to the presence of herbivores by vibrations that run throughout the trees when an animal gets too close or begins to chew. As a result, the insects begin patrolling the acacia’s branches more actively. Remarkably, the researchers show, the ants don’t react when the trees’ movements are caused only by the wind.