On one hand, there is a gigantic super-city with more than a thousand nest mounds. This ant metropolis functions thanks to cooperation – and by avoiding conflicts between the members of different mounds. As a result, this colony has grown into one of the largest animal societies on Earth, with a population as high as 1.2 billions. It has become a city of peace. On the other hand, we see a single mound city that’s always at war with other single cities nearby. Tens of thousands of ants are killed each year in these intense conflicts. Their fierce and dramatic battles highlight a fundamental difference between the single nest ants and the peaceful ants in the super-colony. The existence of these very different cities of the same species of wood ants so close together puzzles scientists. It challenges what they thought they knew about ants. ’Attenborough’s Ant Mountain’ sheds light on the mysterious origins of these extraordinary cities. Over the course of a year, we experience an ant’s eye view of the unbelievable drama, tenderness and aggression of life in the colonies. We meet a cast of wood ant characters that lead us into their secret lives. We delve into the remarkable mechanisms that have evolved within the super-colony and challenge theories about the evolutionary social behaviour of ants.