Collective behaviors of animals are generally controlled by complex biological mechanisms such as serotonin signaling. Interestingly,  Kocabas lab showed that the collective dynamics of tiny worms C. elegans are purely controlled by physical rules. Bacterial diffusion, aerotaxis, and population density—act together and trigger motility-induced phase separation. This study was published in eLife which is one of the prestigious journals of life sciences supported by the Howard Hughes Medical Institute, Max Planck Society, and Wellcome Trust.

Link:  https://elifesciences.org/articles/52781