Army Ants get their name from the unique behavior of moving in orderly, large formations while systematically destroying or severely injuring every living thing in their path. They kill for food. By shear strength of numbers, 3,000 to 10,000 attacks per hour, they overwhelm all sorts of insects, lizards, large spiders, scorpions, and even snakes.
These “raids” include hundreds of thousands of ants, all with specific jobs, in fan shaped formations that span dozens of feet in front and then narrow to a busy path to the bivouac. Some defend the flanks while others attack and cut up the prey. Then others haul the remains to the rear. Their roadway has three lanes: two going to the front, and one in the middle returning to the rear with the spoils of war. Because they are so effective they must regularly move their camp to find food.
Some people value these warriors as natural pesticides. They leave their houses for a day or two while the ants search and destroy, and then they return to a pest free house. Certain birds and other animals make their living following the raids. In some countries these ants are called “driver ants” because they “drive” fleeing insects and animals across the forest floor as they attack. These frightened escaping creatures become prey for the birds.
When they face a gap or small body of water they create a living bridge (pictured) for others to walk over. They will even spread themselves over holes in the path so others can move more quickly. In a flood they form a ball and float to safety. At the end of each day they form a bivouac with their bodies surrounding their queen. Oh… did I tell they are all blind! Amazing complexity...