Saturday, August 03, 2024

The Ant Doctors

Scientists studying carpenter ants in Florida Camponotus floridanus have made an astonishing discovery. Ants amputate wounded limbs to save the life of their colony mates. They discrimiate between wounds in the lower leg and the those in the upper leg (femur), which require amputation while cleaning the wounds on the lower leg (tibia). These operation are remarkably successful with a 90% survival rate. Wound cleaning has a survival rate of only 75% Ants undergoing amputation of one of their six legs resume normal activities in the nest. This level of discrete medical intervention was previously only seen in humans. 

The new study was published in Current Biology. Researchers think that the behavior may be an evolutionary response to the fact that this species of ant lacks metaplueral glands which secrete antimicrobial chemicals. The behavior is innate or instinctional with no evidence of learning. Researchers conducted experiments in the laboratory to distinguish wound treatment depending on location of the injury. Under X-ray the femur and tibia differ significantly in structure. The femur contains much more muscle mass, which is critical to circulating hemolymph--ant blood. The tibia contains a larger hemolymph channel that allows for much faster spread of pathogens. [photo credit:B. Zijlsta]

Ants play an important role in an ecosystem. They eat other insects, are themselves prey for higher animals, and they recycle nutrients into the soil. Camponotus floridanus make their nests in dead wood. The species is unusually agressive, another adaptation to their normal shaded woodland environment where they are both predator and prey. They can live in disturbed areas close to human habitation, but are not considered a threat to structures since they do not bore holes but prefer existing cavities. Ants also have complex social behaviors as demonstrated by the "ant doctors".