How do ants move?
June 28, 2018
The behavior of social animals, such as insects, is a paradigmatic example of a collective phenomenon that emerges from individual behavior. A research article published by researchers at the Institute for Interdisciplinary Physics and Complex Systems (IFISC, UIB-CSIC) in collaboration with the Center for Complex Systems and Brain Sciences (CEMSC3, Univ. San Martin, Argentina) has analyzed the trajectories of ants in various colonies of Temnothoraz albipennis with the aim of studying the characteristics of their movement.
The research is based on the analysis of openly accessible experimental trajectory data. In this dataset, the position of worker ants in different artificial nests are recorded every tenth of a second. The movement of the ants turned out to be irregular and discontinuous, with multiple stops and accelerations instead of a continuous and constant movement. Once the real path data had been analyzed, a mathematical model was proposed to emulate the observed properties. With the data from both approaches, different statistical parameters of the trajectories are compared, taking into account the duration of the movement, distance covered, and speed.
From this analysis it is observed that the higher the speed of the ants, the more unlikely it is that their next movement will increase in speed, which makes biological sense. In addition, it has also been observed that the movement of each ant is correlated with that of its companions. That is to say, they do not behave as individual and independent entities but the speed of their next move will be determined by how other colony partners move: ants that form the different colonies move at greater speed the more of them there are moving together. This collective property emerges from a certain density value of moving agents and had been predicted in theoretical studies.
The study proposes new ways of approaching the individual and collective properties of social animal trajectories and opens the door to future research in the analysis of animal movement.
Riccardo Gallotti, Dante R. Chialvo. Journal of the Royal Society Interface. DOI: https://doi.org/10.1098/rsif.2018.0223
