A new study revealed that a species of carpenter ant in Florida performed limb amputations on injured comrades to improve survival chances. This behavior was observed in "Camponotus floridanus," reddish-brown ants over half an inch long inhabiting southeastern United States.

Researchers noted that ants treated injured limbs by cleaning wounds with parts of their mouths or amputating damaged limbs. The type of care depended on the injury's location. Severe injuries higher on the leg were always amputated, while lower leg injuries received cleaning and treatment.

Entomologist Erik Frank from the University of Würzburg in Germany, the lead researcher, stated that this was the first observation of non-human animals performing limb amputations on others to save lives. Frank added that the ants' medical care system was the most advanced in the animal kingdom, rivaled only by humans.

These ants made homes in decaying wood and fiercely defended nests against rival colonies. Researchers studied injuries to both the upper and lower legs. Such injuries were common among wild ants of various species during fights, hunting, or predation.

Frank explained that ants decided between amputation or extended wound care. The difference lay in hemolymph flow, a blue-green fluid serving as blood in most invertebrates. Injuries below the leg increased hemolymph flow, causing pathogens to enter the body within five minutes, making amputations ineffective. Higher leg injuries had slower hemolymph flow, allowing time for effective amputations.

In both cases, ants first cleaned the wound, likely applying glandular secretions and sucking out contaminated hemolymph. The amputation process took at least 40 minutes, sometimes over three hours, involving continuous biting at the shoulder.

Amputation survival rates ranged from 90 to 95 percent for upper leg injuries, compared to 40 percent for untreated injuries. Lower leg injuries cleaned only had a 75 percent survival rate, compared to 15 percent for untreated injuries.

Wound care was observed in other ant species, which applied glandular secretions with antibiotic properties. However, this species lacked these glands.

Ants had six legs and could function fully after losing one leg, with female ants performing this work. Frank noted that all worker ants were female, and males played only a minor role in colonies, mating with the queen once and then dying.

Frank addressed why ants performed amputations, suggesting it challenged definitions of empathy. He believed ants did not exhibit compassion but had an evolutionary reason for caring for the injured, conserving resources. Rehabilitated workers became productive colony members, making it valuable. Severely injured individuals were not cared for and left to die.