Samneric choose to join Ralph and Piggy in Chapter 12 of "Lord of the Flies," after they are captured by Jack's tribe and forced to betray Ralph's hiding place. They express regret for their actions and seek safety with Ralph's group.
In chapter 8 of "Lord of the Flies," the boys who stay with Ralph are Simon, Piggy, and Samneric. They choose to remain loyal to Ralph and help him maintain order on the island.
Samneric and Piggy.
Ralph does not have a 'tribe.' Jack calls his group of hunters his tribe but Ralph has no name for the boys who originally elected him as their chief. By chapter 10: the only named biguns who still remain near the shelters with Ralph are Piggy and the Twins, Samneric.
Ralph told Samneric that he would hide out in the bushes, so eventually Samneric squeal on Ralph to Jack.
In Chapter 8 of "Lord of the Flies," the boys who stay with Ralph are Piggy, Samneric (Sam and Eric), and a few littluns. They remain loyal to Ralph, even as the group dynamic begins to shift towards Jack's savage tribe.
Ralph learns of Jack's plans for him through Samneric, who are forced to join Jack's tribe and spy on Ralph's group. Samneric bring Ralph news of Jack's intentions to hunt him down and kill him. This betrayal shows Ralph the extent of Jack's animosity towards him.
Samneric ratted Ralph out because Ralph was torturing them.
During the confrontation in "Lord of the Flies," Samneric betray Ralph's trust and align themselves with Jack's tribe. They give away Ralph's hiding place to the other boys, leading to Ralph being hunted like prey. Ultimately, Samneric are forced to participate in the hunt for Ralph against their will.
Most of the boys have joined Jack's tribe leaving only Piggy and the twins, Samneric, remaining loyal to Ralph.
Samneric ratted Ralph out because Ralph was torturing them.
At the end of chapter eleven samneric were taken by Jack and his tribe and forced to join Jack's tribe. In twelve they have to work with the tribe to try and find Ralph on the island. Nothing real serious happens to them. they don't get hurt of killed.
Ralph learns from Samneric that Jack plans to have his tribe hunt him the next day and that Roger has sharpened a stick at both ends.