An international team of researchers has found that Florida carpenter ants (Camponotus floridanus) not only clean the wounded leg of a nestmate (many species of ant do that), but amputate it below the knee, greatly improving the patient’s chance of survival. The operation takes around 40 minutes. The behaviour is innate (i.e. instinctive, not taught/learnt), and has evolved to combat infection, which can spread through the colony.

If the wound is on the tibia (i.e. above the knee) the ants don’t amputate, but only clean. The researchers calculate that a 40 minute operation is too long to prevent pathogens spreading throughout the affected ant’s body, and would therefore be pointless.

Ants are the only animal apart from human beings known to perform lifesaving amputations, and adjust their action according to the location of the wound.