In the animal kingdom, the use of social distancing to counter the spread of pathogens or parasites is more widespread than one thinks. Although this is a behavior that implies high social costs, as unfortunately experienced during the Covid-19 pandemic, the widespread use of this strategy in nature suggests that the benefits outweigh the costs.
The documented cases of this behavior concern animals very different from each other and separated by millions of years of evolution: from baboons less likely to clean the fur of individuals affected by gastrointestinal infections, up to some species of ants which, if infected with a pathogenic fungus , they isolate themselves at the edge of the anthill. Recently, an international team of researchers coordinated by Michelina Pusceddu, Ignazio Floris and Alberto Satta of the Department of Agriculture of the University of Sassari, in collaboration with University College London, the University of Turin and Martin Luther University Halle-Wittenberg (Germany), carried out a study to evaluate whether the presence of the ectoparasitic mite "Varroa destructor" in colonies of honey bees induced changes in the social organization such as to reduce the spread of the same parasite inside the hive . The study, just published in Science Advances, shows that infested bee colonies react by changing the use of space and interactions between nestmates in order to increase social distancing between the cohort of juvenile bees (who care for of the queen and of the brood) and that of the older foragers.
The colonies of honey bees, in particular, are organized into two main compartments: the peripheral one occupied by foragers (elderly bees) and the innermost one composed of young bees, the queen and the brood. This spatial segregation within the colony leads to a lower frequency of interactions between the two compartments than within each compartment and allows the individuals most important for the survival of the colony to be protected from the external environment and therefore from the arrival of diseases.
(Unioneonline / vl)
