For the ant Temnothorax curvispinosus, house-moving is one of the most challenging tasks its colony faces.
Its future success depends on finding a home that offers the right physical environment. At the same time, choosiness must be balanced with speed. In most cases, consensus must be reached among hundreds or thousands of individuals, lest the colony should divide among multiple sites to the detriment of all. Crucially, all of this must be achieved without well-informed leaders or central control.
When there are multiple nests, some better than others, ant colonies have been shown to make rational decisions collectively (Edwards and Pratt, 2009). The process of making the decision is similar to the honey bees described in our previous communication. Essentially, a group of ant scouts go out. Each get to experience a number of nests. Some nests are better than other ones. How good the nest is influences how persuasive the ants are at convincing other ants to go visit it. This simple process of positive feedback results in the best global nest chosen collectively.
The reason the decision works well is because each ant has a limited number of nest options that it knows about, and the ability to influence only a portion of its nestmates. Just like bees, there’s an unusually well-distributed information and power structure among the scouting ants. But when the information and power are distributed unequally, the group decision is more likely to be irrational.
Of course, this asymmetry of information and power doesn’t naturally occur in bees or ants, but it does occur in other organisms. And these organisms might still be attempting to make decisions collectively. Pancake Research Institute is going to hold a session this Sunday 9am to discuss and brainstorm on a simple mathematical model to study this issue. Whiteboards will be provided, as well as pancakes.
Sunday 9am. Join.
Pancake Research Institute
Figure caption. Recruitment behavior used in emigration by Temnothorax colonies. (a) Tandem run, in which a single ant is slowly led to a candidate site. (b) Social transport, in which a single nestmate is rapidly carried to the new site.
