Montana Public Radio

Bug Bytes: When 'Follow The Leader' Turns Deadly

Jun 3, 2019

There are many games you probably played as a child. Games that for all intents and purposes were innocent and safe. But who would imagine that a game of “follow the leader” could be deadly?

It certainly can be for army ants. In fact, it can actually result in the death of the entire swarm.

Army ants are unusual in several regards. First, unlike most other species of ant, they are blind. Second, they don’t have permanent homes. Instead, they are constantly on the move, navigating together as a swarm on the march in search of food. To work together, this visually challenged army plays follow the leader, with the lead ant leaving behind a pheromone trail for other ants to detect and instinctively follow.

This usually works extremely well for these capable foragers who are known for capturing and consuming prey ranging from insects to birds. But in rare instances the game can go terribly wrong.

If a wayward leader mistakenly creates a circle by beginning to follow the scent trail of an ant in its own swarm, they will form an endless loop called an "ant mill" or "ant death spiral." If the loop isn’t broken for some reason, the swarm will never escape this never-ending circle and march until exhaustion and death.

So while there are obvious benefits to working together for many species, including us humans, it’s good to remember that there can also be a price for blindly following those in front of you. Every once in a while it’s good to take a look around to make sure you are indeed headed in the right direction.

BugBytes is made possible by the Missoula Butterfly House and Insectarium, and Montana Public Radio. This show is also supported by funding from the Greater Montana Foundation: Encouraging communication on issues, trends and values of importance to Montanans.