A study has revealed how ants can perform life-saving emergency surgery on each other.
The Florida Carpenter can save its fellow ants from infection with lengthy and simple surgery.
These amputations are particularly beneficial for injuries to the femur, as they significantly increase the likelihood of survival.
Additionally, the spread of pathogens is slower in femur injuries than in the more distal tibia.
Remarkably, ants can differentiate between types of wounds and adapt their treatment strategies accordingly.
In the study published in the journal Current Biology, researchers discovered the habit and found that surgery aided the ant’s recovery with ‘healthcare’ personalised to each injury.
Dr Erik Frank, first author and behavioural ecologist at the University of Würzburg, said: ‘When we’re talking about amputation behaviour, this is the only case in which a sophisticated and systematic amputation of an individual by another member of its species occurs in the animal kingdom.’
This type of behaviour isn’t necessarily new to ants. A paper published in 2023 discovered that an entirely different group of ants, the Megaponera analis, found in Sub-Saharan Africa, uses a special gland to inoculate injuries with a compound that limits possible infections.
The Florida Carpenter ants either clean wounds with their mouths only or perform a cleaning followed by a complete leg amputation.
The researchers discovered the ants used a form of assessment to decide which option was best.
The study analysed two types of leg injuries – lacerations on the femur (thigh) and those on the tibia (shin). All femur injuries were accompanied by a nestmate's initial cleaning of the cut, followed by a separate ant chewing off the leg entirely.
Luckily for the ants with tibia injuries, only a bit of mouth cleaning was required to treat their wounds. In both cases, intervention resulted in ants with a much greater survival rate.
Dr Erik Frank said: ‘Femur injuries, where they always amputated the leg, had a success rate around 90 or 95 per cent. And for the tibia, where they did not amputate, it still achieved about the survival rate of 75%.’
In cases where help wasn’t applied, there was less than 40% survival for femur injuries and 15 per cent for tibia.
The team believes that the ants were choosing wound care paths based on the risk of infection at the wound site.
Micro-CT scans of the femur showed that it is mostly muscle tissue. This suggests that it is crucial for pumping blood from the leg into the main body.
An injury to the femur would compromise the muscles, reducing their ability to circulate potentially bacteria-laden blood.
Conversely, the tibia has very little muscle tissue and wouldn’t be as involved in blood circulation.
The ants can diagnose a wound, see if it's infected or sterile, and treat it accordingly over long periods by other individuals – the only medical system to rival that would be the human one.
The team is now running similar experiments with other ant species to see how conserved this behaviour is.
Given the long duration of these surgeries, the study also raises questions about ants’ abilities to withstand pain.
You can watch the ants at work here.
