Ants Can Perform Life-Saving Amputation On Injured Nest Mates, Study Says

Recent research reveals that an ant in need of help due to a broken limb would quickly resort to another ant, which would bite its broken limb to save its life.

This behavior demonstrated that ants are so far the only creatures other than humans that cut off their own body parts for medicinal purposes.

Amputated Procedures

The primary author of the study, Dr. Erik Frank, who is a lecturer at the University of Lausanne, said that ants could minimize the lives of the injured ants as much as possible by assessing and treating their wounds, to some extent.

The researchers removed the right hind limbs of Florida carpenter ants, Camponotus floridanus, and then observed how fellow ants within the nest responded.

The results revealed 13 out of 17 ants with thigh or femur injuries had their legs cut off by their mates within the trochanter, which is the skeletal structure connecting the thigh with the hip.

These researchers observed this process where nest mates licking the injured area moved up the injured part using their mandibles to the trochanter, the joint between the hip and the femur of this insect, and subsequently these ants bit it till it broke off.

On the other hand, none of the nine ants that had wounds on their tibia, or lower leg, had any amputations. Rather, the only wound treatment these ants received from their nestmates was licking.

When the setup was carried out again using ants that had infected wounds, the scientists noticed identical outcomes.

An additional series of tests showed that, compared to ants with sterile wounds, solitary ants with infected wounds had a significantly higher chance of dying.

But if the injured ants were either sent back to their colonies, indicating that the care offered by their nest mates was helpful, or if the researchers severed the affected limb, well, that helped only with thigh wounds, their chances of survival increased significantly.

Social Insect Workers

Frank stated that initially, it seemed paradoxical that amputations did not also help wounds on the lower legs. Further research, however, indicated that damage to structures that pumped a blood-like liquid around the ants' bodies was linked to thigh wounds but not lower-leg wounds.

Because of this, infections in the lower leg spread throughout the body far more quickly than those in the thigh, hence, amputation of the former did not significantly increase survival.

He also added that ants are more likely to get injuries during territorial conflicts with nearby colonies, although tending to the injured has advantages.

"We see in these Camponotus species that roughly 10-11% of the ants that go out hunting or looking for food carry an injury from a previous day. So they still make up an important part of the colony," he said.

Prof. Francis Ratnieks of Sussex University said he was not surprised by the results. He stressed that this is how social insect employees operate within the colony, helping each other as need may be while benefiting the entire community.