Probably for a number of reason. Ralph had lead the way onto Castle Rock, when at the time it seemed as if the beast must be there. Jack had then insisted that they climb the mountain, despite Ralph's protests that it was getting dark. Finally Ralph had probably had enough of Jack's needling remarks over the course of the day and decided to call his bluff when Jack said he'd go by himself.
Ralph and Jack both insist on going after the beast in order to prove their bravery and demonstrate their leadership to the other boys. They are also motivated by the fear of the unknown and the need to confront and defeat the source of that fear.
Because he is no longer in control
Ralph
How to go about hunting the beast.
It really depends on which part of the book your referring to, but i believe it is the beast that is up there or what they assume to be the beast.
ralph to piggy
In Ch 5 of Lord of the Flies, Ralph says there are no monsters on the Island. Piggy agrees with him. Simon says the beast is within them.
Jack used the beast to gain followers, the littleuns. He manipulated them through their fears to gain power over Ralph.
Ralph, Jack, and Simon are the three main boys who explore the island in "Lord of the Flies." They play significant roles in the novel and each represents different aspects of human nature.
i guess its beast since Ralph and fatty wanted to get the idea of the presence of the beast out of the little boys' heads.
The quote "I don't believe in the beast, I just don't" is spoken by Simon in William Golding's novel "Lord of the Flies." Simon is a character who perceives the true nature of the "beast" on the island as a representation of the inherent evil within mankind.
Simon was not the only one who doubted the existence of the beast. At the meeting where the beastie was first raised Ralph insisted, "But there is no beast." Ralph also called another meeting to settle once and for all that there was no such thing as a beast. At that meeting Piggy also refuted the possibility of a beast by stating that "Things wouldn't work, radios and TV and things, they wouldn't make sense if there were beasts and ghosts and stuff, its not scientific." After Ralph called for a vote to decide if there might be such a thing as the beast Piggy stated, "And remember that I voted NO for the beast."
Ralph feels that it is his duty as chief to cross the causeway to castle rock alone, so that if the beast is there only one boy, himself, will be at risk.
Ralph suggests building a signal fire to attract passing ships for rescue and keep the beast at bay. He believes that maintaining a smoke signal will increase their chances of being rescued and dispel the fear of the beast among the other boys.