2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
One of the authors of work with an artificial experimental nest for ants.
A group of biologists from the University of Bristol found that the ant colony of Temnothorax albipennis behaves as a whole under conditions of simulated attack by predators. It has emergent properties and two types of reactions are observed - depending on the external or internal localization of the threat in relation to the ant nest. In the first case, ants gather inside the nest, and in the second they migrate to a new place. According to the authors, this nature of the reactions makes it possible to call the insect colony a "superorganism". The work was published in the journal PLoS ONE.
Scientists have studied 30 ant colonies, numbering from 96 to 132 individuals in each. The colonies were divided into three groups - one control and two experimental. All colonies were placed by biologists in specially designed transparent artificial nests, a third of which were equipped with special holes in the lid for extracting the ants outside.
For the first experimental group, biologists modeled an external attack by predators. It is known that Temnothorax albipennis, like many other species of ants, are divided into scout and forage individuals. The scouts are exploring the territory and looking for new sources of food, where the foragers are escorted. The foragers who have learned the route then train their other companions. Thus, after a while regular "caravans" are sent to the resources found by the scouts.
Scientists simulated the attacks of predators by temporarily removing all scout ants that left the nest. It turned out that in this case, as if all the scouts had suddenly died at once, the forager ants hastily returned back to the nest, but did not try to emigrate from it.
The second experimental group simulated an attack inside an anthill by removing about 16 percent of the working ants from a hole in the lid. It turned out that with this development of events, the scouts begin to search for a new nest, and then the entire colony migrates there.
In other words, under the condition of any external threat, ants cease to perform their routine functions, expressed, albeit in purposeful, but rather chaotic activity. They abruptly unite and begin to behave as one single organism - to hide and wait, or to evacuate the entire colony.
The key point for the authors here is that none of the ants can count and control all the rest of their colony counterparts. And nevertheless, as soon as losses (for example, inside the nest) reach a certain threshold, the behavior of ants changes dramatically - they migrate. Such properties, which suddenly appear in complex systems (which certainly include the colonies of collective insects), are called emergent. They are not inherent in individual elements of the system or their mechanical sum, but arise as a special systemic effect.