While humans tend to ignore the wisdom of elders and prefer to put them out to pasture, it appears that ants don’t believe seniors are over the ant hill – instead, they respect and use the knowledge of their elders when it comes to finding food and determining the best route back to the nest.
This surprising information came from a new study on how individual ants behave chaotically but the collective swarm seems to act almost intelligently. Researchers from Beijing University and the Potsdam Institute for Climate Impact Research analyzed all available data on ant foraging. They found that scout ants search for food randomly and most come back empty-handed. However, the few that find food bring a piece back and leave a scent trail of pheromones.
As the scouts go back out, they begin to follow the trails and make more of them. Because the pheromones evaporate quickly, the shorter trails have the strongest scent. Gathering ants are then sent out and, as they follow the trails, chaos becomes organization and the end result is the straight lines we see from picnic basket to ant hill.
It had been thought that dangerous jobs were given to older ants because they were less valuable to the colony. However, the researchers found that senior ants have more knowledge about the surroundings accumulated from past foragings so their initial success rate is higher than younger ants. Rather than doing things their way, the younger ants benefit from this wisdom, find food more quickly and learn the area for future excursions.
The results of the study will be published in the Proceedings of the National Academy of Sciences. Co-author Jürgen Kurths summarizes it:
While the single ant is certainly not smart, the collective acts in a way that I'm tempted to call intelligent. The principle of self-organization is known from for instance fish swarms, but it is the homing which makes the ants so interesting. The ants collectively form a highly efficient complex network. And this is something we find in many natural and social systems.
Unfortunately, ants do not have high hopes that we’ll follow their lead on respecting our elders’ wisdom.