Dorylus, also known as driver ants or safari ants, is a large genus of army ants found primarily in central and east Africa, although the range also extends to southern Africa and tropical Asia. Unlike the New World members of the former subfamily 'Ecitoninae' (now 'Dorylinae'), members of this genus do form temporary anthills lasting from a few days up to three months. Each colony can contain over 20 million individuals. As with their New World counterparts, there is a soldier class among the workers, which is larger, with a very large head and pincer-like mandibles. They are capable of stinging, but very rarely do so, relying instead on their powerful shearing jaws.

Such is the strength of the ant's jaws that, in East Africa, they are used as natural, emergency sutures. Various East African indigenous tribal peoples (e.g. Maasai moran), when suffering from a gash in the bush, will use the soldiers to stitch the wound by getting the ants to bite on both sides of the gash, then breaking off the body.

This use of ants as makeshift surgical staples creates a seal that can hold for days at a time, and the procedure can be repeated, if necessary, allowing natural healing to commence

More Info: en.wikipedia.org