Contaminated ants take "sick days" to protect their colony

Scientists believe that ants change their behavior – and they have the same bug as taking a day off sick – when exposed to pathogens to protect the colony.

The research, published in the journal Science, It is believed that these are the first to show that animals can modify their behavior to stop the spread of infectious diseases in their highly united and densely populated communities.

Ants need to balance communication with each other while preventing disease from spreading so that their societies can function, explained the authors of the document.

These societies are complex, insects belonging to different groups depending on their age and role. Young nurse ants are feeding infants, while older workers are venturing out of the nest to forage for food. It is these workers who are most likely to introduce diseases into the colony.

Scientists have tagged thousands of ants in total to quantify all interactions between individuals and understand how colonies can protect themselves from the disease.

Timothy Brütsch

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The researchers tried to ascertain whether the presence of a pathogen (in this case, a fungus) in the social network was affecting the behavior of black ants.

To do this, they tagged tens of thousands of ants in 22 colonies and used infrared cameras to study their movements. A 10% sample of the colony was then exposed to a fungus. The team has been watching closely to see if their actions have changed.

They found that ants behaved prophylactically or flexibly to protect their colony from diseases, especially the important queen and nurses.

Sylvia Cremer of the Institute of Science and Technology of Austria (IST Austria) explained in a statement: "Ants change the way they interact and with whom they interact".

"Ants cliques are getting stronger and clan contact is reduced, foragers interact more with foragers and nurses with nurses, it's a reaction of the whole colony – animals that are not treated with spores also change behavior. "

In addition, it created a process similar to vaccination in humans.

Nathalie Stroeymeyt, the first author of the study and a postdoctoral fellow of the Keller group, told Newsweek: "A surprising result has been that changes in social networks triggered when ants detect the pathogen not only reduce the risk that nurses and the queen will receive a high dose of potentially life-threatening pathogens, but also increase their chances of receiving a low dose of pathogens, which does not cause mortality but leads to vaccination (ie, protection against secondary exposure to the same pathogen, which can to be compared to the vaccination process in humans). "

The study did not determine whether sick ants stopped working for the sake of their nest mates, explained Stroeymeyt, as the tracking system recorded the location and location of the animals. orientation of ants, not their detailed behavior.

But an ant that isolates itself "would be equivalent to being away from work in the sense that it would reduce contact with contaminated colleagues," she said.

So, are we humans – who are sometimes guilty of being reluctant to go to work when they are sick – can learn something from these intelligent ants?

Laurent Keller, professor of evolutionary ecology at the University of Lausanne, declared Newsweek: "Indeed, it is probably logical, from a biological point of view (and economic?) For people with an infectious disease to stay at home until they no longer contagious, instead of coming to work and contaminating their colleagues.