The first time Jack wasn't able to kill the pig, it had become an obsession now, when the time finally came, his hands were stained by the blood of a living body, he loss his innocence.
Man's inherent evil, is the main topic of this novel, when a kid, a pure soul, takes part is such violent act, and chants gruesome lines as if a religious act, we wonder how the environment might just have made the evil their god, meant to be worshipped.
This cell contains the scenery of the first time when Jack made others question his humanity by flaunting the horrible way the pig had been killed, even at this time when they lost the chance of being rescued because he let the fire out.
Simon's secret place,first, it has natural beauty and peace, but when Simon returns later in the novel, he discovers the bloody head. It shows when humans enter, their evilness takes over the innocent environment.
Robert was acting like a pig, other boys were so unconscious that they nearly killed Robert, think of it like a pig. The boys slow evil instinct was so smooth that it went unnoticed.
The loss of innocence isn't only killing. Its every small actions like throwing rocks at a lil un or even mocking and disrespecting piggy.These all play role in staining ones pure and innocent soul.