Florida Carpenter Ants Are the Only Insects Known to Amputate Limbs

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When a Florida carpenter ant suffers a leg wound near the femur, its colony mates do not simply clean the injury — they gnaw the limb off entirely above the wound site. This is the first documented case of a non-human animal performing surgical amputation on another member of its own species. Biologist Erik Frank at the University of Würzburg discovered the behavior after bringing the ants into his German lab and deliberately wounding their legs. He repeated the experiment four times before accepting the result, calling it "very counterintuitive." The survival rate speaks for itself: ants that received the amputation survived at a ninety percent rate, while those left isolated survived at only forty percent. The reason the procedure is viable at the femur but not the tibia comes down to ant physiology. The femur has denser musculature that slows the flow of hemolymph — insect blood — giving nestmates enough time to perform the operation before bacteria spreads. Tibia wounds, where circulation is faster, require a different response: licking the wound to remove bacteria directly with the tongue. Florida carpenter ants lack the antimicrobial glands most ant species possess, having lost them through evolution, which may have driven this extreme alternative strategy.