I’ve just read an article in The Times newspaper. It is the kind of article which makes you completely review your personal thoughts and concepts about ants and indeed other insects. Yesterday I was sweeping my patio and while I was doing so, I swept up some ants. Nothing to concern anybody. They’re just ants, right?
Now let me explain what The Times has reported to me this morning. The entire description makes one believe that one is writing about people not ants as their behaviour is so advanced and so considerate of others.
German and Swiss researchers said that their research showed “literally the only case” that they had ever seen of one creature “performing a sophisticated and systematic amputation on another member of its species as a means of wound care”.
The scientists studied Florida carpenter ants. These are a common species event in Florida, America and they found that the ants “selectively treat” wounds on fellow ants, their comrades.
The researchers hail from the University of Würzburg in Germany and the University of Lausanne in Switzerland.
They examined two types of injury incurred by ants. One concerned lacerations to either the upper part of the leg at the femur (thigh bone) and the other concern the lower part of the tibia (shin bone). Like I said, this is like talking about people.
Comrade ants used their mouthparts as a means of cleaning out a cut incurred in tibia injuries.
With respect to femur injuries, the cut was also cleaned out but was followed “by a nestmate chewing off the leg entirely”.
This was about improving survival because when one ant received a femur injury the survival rate was about 40% but this rose to 90% if the amputation was performed.
Concerning the tibia injuries the survival rate was 15%. This rose to 75% if the injury had been cleaned out by a comrade.
The study is published in the journal Current Biology. The researchers found that bacteria entered the ant from the exterior faster through a tibia injury. This is because of faster blood flow in that part of the body. The ant’s femur has more muscle which can slow the blood flow after an injury. This in turn reduces the spreading of the disease.
Fellow ants spend more time cleaning a wound to the lower leg because of the speed at which bacteria can spread from a tibia injury. They clean the wound carefully rather than opting for amputation which can take up to 40 minutes.
The author of the study, an evolutionary biologist, at Lausanne, Laurent Keller, said: “Because they are unable to cut the leg sufficiently quickly to prevent the spread of harmful bacteria, ants try to limit the probability of a lethal infection by spending more time cleaning the tibia wound.”
When we are talking about amputation behaviour, this is literally the only case in which a sophisticated and systematic amputation of an individual by another member of its species occurs in the animal kingdom.”
Erik Frank the lead author and a behavioural ecologist at Würzburg.
