Watch a carpenter ant chew off another’s wounded leg to try to save its life

It’s not just humans who try to heal wounds—some carpenter ants also engage in wound cleaning and even amputations. A recent study published in Current Biology on July 2 revealed that these ants may tailor their treatment based on the type of injury.

According to study co-author Erik Frank from the University of Würzburg, the amputation behavior observed in these ants is unique in the animal kingdom. While other ant species like Megaponera analis use antimicrobial compounds to clean wounds, Florida carpenter ants rely on mechanical means.

The study found that the ants follow two main methods of wound care: cleaning with mouthparts or amputation of the affected leg. The choice of treatment seems to depend on the type of injury, with femur injuries leading to amputation and tibia injuries receiving only cleaning.

The researchers discovered that the survival rate of ants with experimentally infected wounds was much higher when they received proper treatment. This suggests that the preferred treatment route may be related to the risk of infection from the wound site.

Micro-CT scans revealed that femur injuries could impede blood circulation due to muscle tissue composition, making them more susceptible to infection. In contrast, tibia injuries had less muscle tissue involvement, allowing bacteria to enter the body faster.

Interestingly, the speed of amputation plays a crucial role in preventing lethal infections. The team observed that ants can take up to 40 minutes to amputate a leg, leading them to spend more time cleaning tibia wounds to limit the spread of harmful bacteria.

The researchers believe that the ants’ ability to diagnose and treat wounds makes their medical system comparable to that of humans. Further studies are needed to understand the mechanisms behind these sophisticated behaviors.

According to Laurent Keller, an evolutionary biologist from the University of Lausanne, ant behaviors are mostly innate, with little evidence of learning. The team plans to investigate other Camponotus species to determine the extent of this behavior across ant species.

Overall, the level of innate cooperation observed in these ants is quite impressive, highlighting the complexity of their social behavior and care for injured nestmates.