In chapter 4 page 81 Golding states, "We needed meat!"
"Jack stood up as he said this, the bloodied knife in his hand. The tow boys faced each other. There was the brilliant world of hunting, tactics, fierce exhilaration, skill; and there was the world of longing and baffled commonsense."
Jack is the hunter, exhilarated by his accomplishment in bringing meat to the tribe, but Ralph is baffled because he doesn't understand why the boys can't see that if they had kept the fire going the ship would have seen them and they could be going home. If the ship had rescued them there would be no need for the hunting.