Researchers in the southeastern United States have made a fascinating discovery about the behavior of a species of ant that bears similarity to a medieval medical practice. Their findings suggest a level of sophistication in caring for injured nestmates that is unparalleled in the animal kingdom. According to Erik Frank, a behavioral ecologist at the University of Würzburg, the ants have evolved to perform amputations on each other when facing severe injuries, effectively preventing the spread of infection from open wounds and saving lives. This behavior marks the first known instance of a nonhuman animal conducting amputations to aid an injured member of its species.
Published in the journal Current Biology, the study found that Florida carpenter ants, known scientifically as Camponotus floridanus, demonstrate a remarkable ability to distinguish between different types of wounds and adjust their healing responses accordingly. The scientists observed the ants performing amputations in laboratory settings, noting that these reddish, black, or brown ants, measuring under 1/2 an inch in length, lack the ability to produce antimicrobial secretions to combat pathogens in wounds. This led to the question of how the species compensates for this limitation in caring for their injured.
The researchers conducted experiments by deliberately injuring around 100 ants on either the femur or tibia, comparing the responses of fellow colony members. They found that the ants consistently performed amputations on nestmates with femur injuries but not on those with tibia injuries. The amputation process, lasting around 40 minutes, involved a specific pattern of licking and biting the wound until the leg was severed. The study revealed that 95 percent of ants that received an amputation for a femur injury survived, demonstrating the effectiveness of this form of treatment.
Interestingly, the decision on when to perform an amputation appears to be linked to the flow of hemolymph, an insect’s equivalent to blood, within their bodies. Observations showed that the tibia area of the leg has a higher hemolymph flow than the femur area, suggesting that pathogens could spread more rapidly through the tibia and pose a greater risk of infection. As a result, the ants seem to prioritize amputations for injuries involving the femur to prevent widespread infection.
The study also highlighted the cooperative nature of social insects like ants, showcasing how altruistic behavior benefits the entire colony. Laurent Keller, an evolutionary biologist involved in the study, emphasized that by assisting injured nestmates, the ants indirectly support the well-being of the colony as a whole. This form of mutual aid within ant societies not only contributes to the survival of individual members but also enhances the overall productivity and resilience of the colony.
In conclusion, the research sheds light on the remarkable capabilities of ants in caring for their injured companions and highlights the evolutionary advantages of such cooperative behavior within social insect communities. The ability of these tiny creatures to conduct life-saving amputations and provide essential wound care underscores the intricate dynamics of ant societies and their collective approach to overcoming challenges.