Ants take their health very seriously and the health protocols they must follow to avoid infections. Only in recent years have we discovered that there are species in which sick specimens are quarantined, but also that they are able to operate on their injured companions, performing surgical operations or even amputations.
Now, thanks to a study published on Nature Communicationswe also know that ants are honest when it comes to health: if they get sick, they notify their companions, who react accordingly (and now you will see how…).
Ants and mushrooms. The subjects of the study, conducted by a team from ISTA (Institute of Science and Technology Austria), were a colony of ants of the species Lasius neglectusoriginally from Asia but now also introduced in Europe, including Italy. They are ants that form very large colonies, which can host 35,000 queens and up to 100 million workers: in such crowded contexts, health safety is essential.
The team then tried to understand what happens when a pupa gets an infection. Their experiment involved infecting some pupae with a fungus, and treating others with a harmless but very odorous substance. Afterwards, the pupae were put in contact with adult workers, who normally take care of their well-being and growth.
A sacrifice for the common good. While the “placebo” ants were treated like all other pupae, the fate of those infected by the fungus was much more cruel. In fact, when the pupae understand that they are sick, they emit an odorous alarm which alerts the entire colony and “activates” the workers who have to take care of the sick person.
How do they do it? Disinfecting it: the ants tear the pupa from its cocoon, make small cuts on the surface of its body and inject formic acid, which serves as a disinfectant.
The advantage of this method is that formic acid kills pathogens instantly. The side effect is that it also kills the pupa, which when it signals that it is sick, therefore knows that it is about to meet its fate. A gesture that serves to preserve the health of its companions, with whom the pupa shares several genes: it is a necessary sacrifice to prevent an infection from spreading and putting the entire colony at risk.
