roger and jack decide to cut off the pigs head and mount it on the sharpened stick as a gift to the "beasty"
Roger has prepared a stick sharpened at both ends for Ralph. This means that he has the same end in mind for Ralph as the sow (female pig). The sow was killed rather brutally killed prior to having her decapitated head mounted on a stick sharpened at both ends as an offering to "the Beast." This is a thinly vailed threat on Roger's part.
They warn Ralph that Jack plans to hunt him the next day and that Roger has "sharpened a stick at both ends."
Samneric tells Ralph that Roger sharpened a stick at both ends. This means that when they kill him, they will put him on the stick like the pig's head.
-Spoiler warning- The only other time a stick is sharpened at both ends is after Jack killes the sow and offers the head to the beast for protection. It means that Roger wants to murder Ralph, cut his throat, and put his disembodied head on the stick as an offering to Satan.
When Samneric mention that Roger sharpened a stick at both ends in "Lord of the Flies," it signifies the increasingly violent and dangerous nature of Roger. Sharpening a stick at both ends suggests a malicious intent to harm others, foreshadowing the savagery that will eventually consume the boys on the island. It also symbolizes the loss of civilization and the descent into barbarism.
The pigs head, which was offered to the beast, was mounted on a spear which had been sharpened at both ends. One point to hold the head and one point to stick into the ground. The implication is that Jack intends to behead Ralph and then mount his head on a stick as an offering to the beast.
Jack and Roger have sharpened a stick at both ends to hunt and kill Ralph. Their plan is to hunt Ralph like they did with the sow, to terrify him and flush him out. Samneric warn Ralph that they are being hunted and that Jack's tribe will sharpen a stick at both ends and have Roger guard the way in.
When Jack and his hunters killed the Sow, Jack ordered that a stick should be sharpened at both ends, so that he could stick one point in the ground and mount the sow's head on the other point, to leave it as an offering for the beast. As it turned out the ground was rocky and the stick was simply jammed into a crack. However, later in the novel, when Ralph asked Samneric what Jack planned to do to him one of the twins told him that "Roger sharpened a stick at both ends." The obvious inference was that Jack and his hunters intended to kill Ralph and mount his head on a stick as an offering to the beast.
Well, they use the first sharpened stick to put the pig's head on. They don't actually do anything with the second stick, but they planned to kill Ralph and stick him on there, just like the Lord of the Flies. Luckily for him, the naval officer came and the suspenseful chase through the woods is ended.
The lord of the flies originally hung on a stick sharpened at both ends. One end in the earth and the other supporting the pig head. Roger intends to do this same thing to Ralph if they kill him, but replacing the pigs head with Ralphs. They dont kill Ralph :)
Technology can be as simple as a sharpened stick.
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.