The colony has been abandoned for a long time and spans an area roughly equal to 500 square feet, with its tunnels and passages spiraling down some 26 feet down into the surface, and is believed to be one of the world’s largest ant colonies, if not the largest.
Nature’s Secret Power, a documentary, speculated that this wondrous engineering structure was the effort of an active community of leafcutter fans, described as essentially a superorganism. It is estimated that the work resulted in over 40 metric tons of soil being excavated to lay the foundations of the inner structure, which is made up of an incredible network of interconnected pathways.
This complex network resulted in the efficient transportation of foraging expeditions, and a great ventilation system from within the structure. The chambers were used to grow fungus gardens and also to dispose of rubbish in dedicated pits. The leafcutter ants would have foraged for any type of vegetation to sustain their internal gardens.
An immense flood of ants, about a hundred yards in width, was pouring in a glimmering-black cataract down the far slope of the ditch. Many thousands were already drowning in the sluggish creeping flow, but they were followed by troop after troop, who clambered over their sinking comrades, and then themselves served as dying bridges to the reserves hurrying on in their rear.
Shoals of ants were being carried away by the current into the middle of the ditch, where gradually they broke asunder and then, exhausted by their struggles, vanished below the surface. Nevertheless, the wavering, floundering hundred-yard front was remorselessly if slowly advancing towards the beseiged on the other bank. Leiningen had been wrong when he supposed the enemy would first have to fill the ditch with their bodies before they could cross; instead, they merely needed to act as steppingstones, as they swam and sank, to the hordes ever pressing onwards from behind…. Leiningen Versus the Ants–Carl Stephenson