Ant Death Spiral - Vortex

[EllJay]

After seeing these clips I thought of a mix between World War Z and the Muslims walk around Kaba in Mecca.

This is one of my favorite things about ants -- the ant death spiral. Actually, it's a circular mill, first described in army ants by Schneirla (1944). A circle of army ants, each one following the ant in front, becomes locked into a circular mill. They will continue to circle each other until they all die. How crazy is that? Sometimes they escape, though. Beebe (1921) described a circular mill he witnessed in Guyana. It measured 1200 feet in circumference and had a 2.5 hour circuit time per ant. The mill persisted for two days, "with ever increasing numbers of dead bodies littering the route as exhaustion took its toll, but eventually a few workers straggled from the trail thus breaking the cycle, and the raid marched off into the forest."

The cause of this behavior is the technology ant societies use for ground navigation. They follow pheromone trails on the ground laid down by other ants, or they simply follow other ants visually. The system works well normally. A scout ant goes out and finds something. Other ants go back to get more by following the scent trail, or by following each other. However, if a loop gets created, the ants will march blindly, sometimes circling until they die.

http://theantroom.blogspot.se/2006/11/ant-death-spiral.html

http://blogs.howstuffworks.com/brainstuff/how-death-spirals-work-in-ants/

[krypter3]

Saw a documentary about these. They actually uses some kind of spray to put a bunch of ants into one, to demonstrate the pheromones.