Carpenter Ants (Camponotus) – Jumping spiders, a diverse genus of large ants that inhabit many forested areas around the world, are able to selectively treat the injured limbs of their nestmates by cleaning or amputating the wounds.

For animals, open wounds pose a significant risk of infection and death. To reduce these risks, many animal species apply antibacterial compounds to wounds.

In 2023, researchers discovered another ant species, Megaponera analis, uses special glands to inject antibacterial compounds into wounds, reducing the chance of infection.

Florida carpenter ant (Camponotus floridanus) and other species of the same genus Camponotus. Notably, they lack such glands and therefore appear to use only mechanical means to treat their nestmates.

Dr. Eric Frank from the University of Würzburg and his colleagues discovered that this mechanical care involves one of two pathways.

The ants either clean the wound using only their mouthparts, or clean it and then amputate the leg completely.

When choosing which route to take, Ali appears to be assessing the type of injury and tailoring the best treatment approach based on information.

The study analyzed two types of leg injuries: femur lacerations and ankle-like tibial lacerations.

All femur injuries involved a nestmate first cleaning the cut and then biting off the entire leg, in contrast to the tibia injuries, which involved only mouth cleaning.

In both cases, the intervention resulted in a significant increase in survival of ants with experimentally infected wounds.

“With femur injuries, we always end up amputating the leg, and we have about a 90 to 95 percent success rate. And with tibia injuries, where we don’t amputate, we achieve about a 75 percent survival rate,” Dr. Frank said.

“This is in contrast to the survival rates of untreated infected femoral and tibial abrasions, which are less than 40 percent and 15 percent, respectively.”

The scientists hypothesized that preferred methods of wound care may be related to the risk of infection from the wound site.

Micro-CT scans of the femur confirmed that it was mostly composed of muscle tissue, suggesting that it played a functional role in pumping blood, called hemolymph, from the leg to the trunk.

When the femur is damaged, the muscles are damaged and the ability to circulate blood that may be contaminated with bacteria is reduced.

The tibia, on the other hand, has very little musculature and little contribution to blood circulation.

“With a tibia injury, the hemolymph flow is less disrupted, allowing bacteria to enter the body more quickly, whereas a femur injury slows down the rate at which blood circulates in the leg,” Dr Frank said.

“If tibial injury would hasten infection, one might expect that amputation of the entire leg would be the most appropriate option, but in fact the opposite has been observed.”

“It turns out that the speed at which the ants can sever the legs makes a difference.”

“An amputation surgery using ants takes at least 40 minutes to complete.”

“Experiments have demonstrated that in the case of tibial injuries, the ants cannot survive unless the leg is removed soon after infection.”

“This means that the ants cannot cut their legs quickly enough to prevent the spread of harmful bacteria, so by taking their time cleaning the wound in their shins they try to reduce a potentially fatal infection,” says Dr Laurent Keller, an evolutionary biologist at the University of Lausanne.

“The fact that ants can diagnose wounds, determine whether they are infected or sterile, and then treat them accordingly over time with other individuals — the only medical system that could match that would be the human medical system.”

Given the sophisticated nature of these behaviors, the next question to ask is how these ants are able to perform such precise care.

“This is all innate behaviour; ants’ behaviour changes as individuals age, but there is little evidence of learning,” Dr Keller said.

of Investigation result Published in the journal Current Biology.

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Eric T. Frank othersIn order to combat infections in the ant community, they amputate legs depending on the injury. Current BiologyPublished online July 2, 2024; doi: 10.1016/j.cub.2024.06.021

This article is based on an original release by Cell Press.