From A History of Medicine by Plinio Prioreschi (Horatius Press, 2002):
An interesting procedure [described in the Sushruta Samhita, an Indian text from the sixth century BC] is the use of the heads of certain ants for the suturing of intestinal perforations:
. . . large black ants should be applied even to the perforated intestines . . . and their bodies should be separated from their heads after they had firmly bitten the perforated parts with their claws [jaws]. After that the intestines with the head of the ants attached to them should be gently pushed back into the cavity and reinstated in their original situation therein.
This procedure is also mentioned in the Caroka Samhita [probably third century BC]:
And if there is a perforation of the intestines, the part should be made to be bitten by big black ants and seeing that the perforation is welll closed by the firm bites taken by the ants, their bodies must be cut off. Then putting the intestines back in their place, the abdominal skin should be sutured with the needle.
Although suturing with ant heads was unknown in Hippocratic medicine, it has been used in primitive medical practices in South America and Africa.