A study published on Tuesday in the journal 'Nature Communications' shows that ant pupae, in the developmental stage between larva and adult, inform other individuals of their illness through a chemical olfactory signal. This mechanism is similar to the one used by the human body: just as an infected cell sends a chemical signal that attracts immune cells, the sick pupa warns the worker ants to eliminate it as a source of infection. Unlike other animals that hide their illness from the herd to avoid being excluded, ants signal when they have an infection so as not to infect the rest of the colony and to be subjected to a disinfection process that they do not survive, according to an Austrian study. After the warning, the worker ants react by removing the sick pupae from their cocoons and making small incisions in their skin to apply formic acid, a self-produced antimicrobial disinfectant toxin. This treatment immediately eliminates the pathogens multiplying inside the pupa, but the pupa does not survive the disinfection, demonstrating that the colony functions as a superorganism in which the whole is more important than the individual. 'It is important that this signal is sensitive and specific,' emphasizes Sylvia Cremer from ISTA, referring to these alarms that are only sent when the brood has lost the battle against the infection, and not when they could still recover. 'These are not volatile substances, but non-volatile odor compounds present on the surface of the pupa itself,' comments Thomas Schmitt from the University of Würzburg (Germany), another author of the research, funded by the EU's Horizon 2020 program.
Ants signal illness to save the colony
An Austrian study reveals that ant pupae emit a chemical signal when sick, prompting worker ants to remove them. This altruistic act protects the colony, much like the human immune system, ensuring the health of the collective over the individual.
