Ants are the poster children for eusociality. Each ant has a job, and each ant sticks to its job: the foragers forage, the workers work, the nurses nurse, the queen procreates. It has been assumed that this strict segregation of ant society into age-and-task groups could help prevent epidemics, but this assumption had never been tested. Finally, a group of scientists got together and figured out how to do the experiment using 22 colonies of Lasius niger, the common black garden ant.

A division of more than labor

The scientists hailed from various departments in various universities: Ecology and Evolution, Science and Technology, Biorobotics, Intelligent Systems, and Physics of Complex Systems. They labeled each ant in each colony with what looked like a paper QR code taped to its thorax and used video tracking to follow individual ants, monitoring all of the physical contacts among them.

As predicted, the structure of the colonies inhibited the transmission of pathogens. The colonies were sorted into discrete communities that were connected, but the nodes at which they were connected were limited. This organization also protected the most vulnerable members: the queen and young workers.