As with humans, wound care plays an important role in the animal kingdom. Many mammals lick their wounds, some primates use antiseptic plants, and some ants even produce their own antimicrobial substances to treat infections.

The latter was demonstrated by biologist Dr. Erik Frank, a researcher at Julius-Maximilians-Universität Würzburg (JMU), in the African Matabele Ant. In a new study, now published in the journal Proceedings of the Royal Society B, he takes a closer look at an ant species that uses a less refined but nevertheless effective approach: amputation.

Erik Frank heads a junior research group in Würzburg funded by the Emmy Noether Programme of the German Research Foundation (DFG) at the Chair of Animal Ecology and Tropical Biology (Zoology III).

Cut first, Ask Questions Later

The study, entitled “Better Safe Than Sorry: Leg Amputations as a Prophylactic Wound Care Behaviour in Carpenter Ants”, focuses on Camponotus maculatus, a species of carpenter ant found mainly in Africa.

“We observed how workers amputated injured limbs of their fellow ants at shoulder height, simply biting off the injured leg with their strong mandibles”, says Frank. It did not matter whether the wound was infected. Nor was the age of the wound a decisive factor in the decision; the ants played it safe when it came to treatment.

“The ants do not have the luxury of waiting for an infection to develop. Once the infection becomes apparent, amputations are no longer able to stop it from spreading throughout the body”, explains Juan José Lagos-Oviedo, doctoral student and one of the two lead authors of the study. The success of this approach proves these pragmatic animals right, with amputations more than doubling the survival rate of injured workers.

Decision-making Processes Comparable to Human Medicine

Since insects such as ants, termites and honeybees live in large colonies, protecting themselves from infections that can spread quickly in their densely populated homes is particularly important for them.

Prophylactic amputations due to a lack of information about the infection status are unique in the animal kingdom and reminiscent of human medical logic.

Work on this topic will be further intensified in the future. In a new research project, doctoral student Seiji Fujimoto will focus on ant species that use both amputations and treatments with antimicrobial substances. “We want to understand this decision-making process and find out how these behaviours evolved. In other words, why only some ant species amputate”, says Erik Frank.