Surgeon ants

The first case of a non-human species deliberately performing medical amputations on its fellow humans has been discovered, helping the operated individual survive.

The authors of the study in which the discovery was made have shown that the ants in question, of the Camponotus floridanus species, popularly known as Florida carpenter ants, perform amputations on injured individuals in their colony in order to increase their survival. The main author of the research, Erik Frank, spoke with the UNQ Scientific News Agency about this discovery: “This is the first species studied in the animal kingdom, beyond humans, that performs amputations as part of a medicinal system.”

Ants use antimicrobial secretions that they emit through a gland called the metapleural gland to fight infections or pathogens. However, throughout the history of evolution, several species have lost this gland, as is the case of the Florida carpenter ant. In this regard, scientists studied how this species deals with infected wounds on its legs.

“We wanted to see how a species that has no antibiotics treats injuries. What we observed is that when the wound is at the level of the femur of the leg, the ants bite the base of the limb for several minutes until it is cut and bacteria cannot enter. The observations carried out revealed that the survival of the injured individual increases from 45 percent (without care) to 95 percent.

However, if the wound is on the tibia of the leg, the ants do not amputate it but perform other types of care. Erik Frank says that it took them about a year to understand why they did not make the cut in the tibia as they had done in the femur. He explains: “Finally, we observed that the blood circulation in ants is different from that of humans. Unlike us, they have many hearts distributed throughout their body and, specifically in the leg, they are located in the femur.”

And he continues: “When they are injured in the upper part, the circulation slows down, whereas when the injury occurs in the tibia, the circulation continues normally, which makes the pathogens enter the body much faster (in less than five minutes). This means that they do not have enough time to perform an effective amputation.”

In this case, the ants perform other types of care to help their colony mate, such as using their tongue to clean the wound and thus remove the infected liquid or trying to clean any dirt they have. “This care also improved survival from 15 percent (in those that do not receive care) to 75 percent (in those that do receive it),” says Frank.

Ants are capable of administering some basic medical care to their injured companions. (Photo: Danny Buffat. CC BY-SA)

The research team, which also includes Danny Buffat, also has other hypotheses in mind, such as, for example, that certain antimicrobial agents could be obtained from ants to treat human diseases. “The Pseudomonas aeruginosa group of bacteria causes infections in humans and current medicine still has problems treating these pathogens. In the case of ants, they have already developed their antimicrobial system to combat the bacteria,” Frank exemplifies, and adds: “We have a lot to learn from their system of medicine.”

The research emerged as a cooperation between the University of Lausanne (Switzerland), the University of Würzburg (Germany) and the Okinawa Institute of Science and Technology (Japan).

The study is titled “Wound-dependent leg amputations to combat infections in an ant society.” It has been published in the academic journal Current Biology. (Source: Luciana Mazzini Puga / UNQ Scientific News Agency)