http://en.wikipedia.org/wiki/Bullet_ant
The pain caused by this insect's sting is purported to be greater than that of any other
hymenopteran, and is ranked as the most painful according to the
Schmidt sting pain index, given a "4+" rating, above the
tarantula hawk wasp and, according to some victims, equal to being
shot, hence the name of the insect. It is described as causing "waves of burning, throbbing, all-consuming pain that continues unabated for up to 24 hours".
The Satere-Mawe people of Brazil use intentional bullet ant stings as part of their initiation rites to become a warrior.[7] The ants are first rendered unconscious by submerging them in a natural sedative, and then hundreds of them are woven into a glove made of leaves (which resembles a large oven mitt), stingers facing inward. When the ants regain consciousness, a boy slips the glove onto his hand. The goal of this initiation rite is to keep the glove on for a full 10 minutes. When finished, the boy's hand and part of his arm are temporarily paralyzed because of the ant venom, and he may shake uncontrollably for days. The only "protection" provided is a coating of charcoal on the hands, supposedly to confuse the ants and inhibit their stinging. To fully complete the initiation, however, the boys must go through the ordeal a total of 20 times over the course of several months or even years