I had never heard of this. Apparently sometimes ants can get caught up in a circle following the ant in front of them and then keep going in a circle until they starve to death.
This is a species of army ant, Labidus praedator. These ants are completely blind so they get about by sniffing trails left by the ants in front of them. They, in turn, leave chemical trails of their own. The system works smoothly when everybody's going in a straight line in one direction...
But when the lead ants start to loop, bad things can happen (and remember we humans loop too, we can't hold a straight course over long distances without external points of reference). If the ant-in-front loops and intersects with its old trail, the whole crowd then turns in on itself and everybody gets caught in the endless circle.
Check out this fascinating video of this in action.
The article mentions that this is something that never happens to humans which is true in a literal fashion. You've never (at least I never have) seen a group of humans stuck endlessly circling about until they die. I have seen people, though, blindly following the lead of someone else. Most people are sheep and don't want to stand out or be the first to do something for fear of looking foolish. They will willingly go along with a crowd even if they have some reservations inside. It's a hard thing to overcome because no one likes to be embarrassed.