Imagine a complex society that can accomplish amazing things, but also has an error in its programming that, occasionally, causes many of its members to run amok and die tragically. This is the situation faced by some species of ants, and the behavior is called a death spiral or an ant mill. You can see several examples in the videos below. The ants seem to have gone insane, walking in an endless circle together.
Here is a nice description:
Ant Death Spiral
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 cycl...