because he does not feel ralphs methods of staying with civilization are working. he wants to hunt and have fun, also he is fed up with being ordered to keep the fire alight.
Jack forms his own group in "Lord of the Flies" because he wants to have power and control over the other boys. He feels rejected by the democratic leadership of Ralph and sees an opportunity to establish his authority by creating his own tribe. Jack's need for dominance and the desire to hunt and act savagely also contribute to his decision to form a separate group.
Jack
The Hunters.
Jack is the leader of the choir and the one who leads the break away group, who split from Ralph's lot to form a tribe.
He calls them his "hunters"
Jack's group in "Lord of the Flies" is known as the "hunters" or the "savage tribe." They are a group of boys who become increasingly violent and aggressive as the novel progresses.
jack overcomes Ralph by making his own group of people and being the leader of his group
Jack promises the Lord of the Flies that he will continue to hunt and kill for it. He also pledges to offer sacrifices to it in the form of the pig's head that he places on a stick as an offering.
Jack orders the boys to kill Piggy and Ralf.
The fire and Piggy's specs
In the book The Lord of the Flies by chapter 9 Ralph, Piggy, and the twins are the people who have not joined Jack's group. After the twins are captured and Piggy is killed that leaves Ralph as the one person who is not a part of Jack's tribe.
The character who is portrayed as savage in "Lord of the Flies" is Jack Merridew. Jack becomes increasingly barbaric as the novel progresses, leading a group of hunters who embrace violence and savagery on the island.
In "Lord of the Flies" by William Golding, the groups separate in Chapter 8 when Jack and his followers split from Ralph's group to form their own tribe. This marks the beginning of the escalating conflict between the two groups on the island.