Carpenter ants have been observed displaying behavior that involves wound cleaning and even amputation to help injured nestmates. This unique behavior was detailed in a study published in the journal Current Biology. According to the researchers, this is the only known case of systematic amputation within the animal kingdom.
While some ant species use special glands to deliver antimicrobial compounds for wound treatment, the Florida carpenter ants in the study rely on mechanical means. They have two methods of caring for injured nestmates – mouthpart cleaning or complete leg amputation. The choice of treatment appears to depend on the type of injury, as the study found that ants with experimentally infected wounds had a higher survival rate when the affected leg was amputated.
The researchers believe that the decision to amputate a leg or not is related to the risk of infection. Femur injuries, which involve amputation, had a higher success rate compared to tibia injuries that only received cleaning. Micro-CT scans showed that the femur is more involved in blood circulation, making it more susceptible to infection if injured. On the other hand, the tibia has less muscle tissue and is less critical for blood flow.
Interestingly, the study found that amputation of a leg takes at least 40 minutes, which may not be fast enough to prevent lethal infection in some cases. Therefore, ants spend more time cleaning tibia wounds to reduce the risk of infection. The researchers suggest that these ants have a sophisticated medical system that rivals human healthcare in terms of diagnosing and treating wounds.
Future studies will focus on understanding how ants are capable of such precise care and whether similar behaviors are seen in other ant species. The researchers are conducting experiments to investigate if all ant species without special antimicrobial glands also perform amputation. They also hope to explore the concept of pain in ant societies, as the ants being treated appear to allow the removal of a limb voluntarily.
The level of innate cooperation and care observed in these ants is remarkable, and further research will shed light on the mechanisms behind these behaviors. The researchers believe that studying these ants can provide valuable insights into wound treatment, infection prevention, and pain perception in social insect societies.
