The division of labor begins in groups with as few as six raider ants (Ooceraea biroi), according to a study published yesterday (August 22) in Nature.
The researchers examined 100 colonies of raider ants, which, unlike other species of ants, do not have a queen and are all workers. By marking these ants with paint patches, the team tracked the ants during a particular phase of colony development when they are highly active. They found that some ants looked for food while others cared for their larvae.
As the sizes of these colonies increased, the ants grew more specialized in their responsibilities—a trait that was linked to a healthier colony with better survival and reproduction rates.
Y. Ulrich et al., “Fitness benefits and emergent division of labour at the onset of group living,” Nature, doi:10.1038/s41586-018-0422-6, 2018.