In chapter 8, Jack gets mad at Ralph and calls a meeting. Jack asks all the boys to raise their hands if they don't think Ralph should be leader and none of the boys did. Jack was furious and stormed away and said he was no longer a part of their group. Jack ends up getting a few followers and they go and kill a mother boar and stick her head on a stick for the Beastie. Ralph and piggy move the fire down hill to their campsite and they start making changes that will better them. Simon names the boar's head Lord of The Flies because she is covered in them. Jack takes fire wood from Ralph and the other boys in the night. And Simon discovers they are the beasts.

http://www.nlm.nih.gov/medlineplus/ency/article/003258.htm

.Hearing sounds, voices, feeling body sensations, seeing patterns or lights, and smelling foul odors are all symptoms.
.Being drunk or high can cause it along with many diseases.
.Could be your body warning you of organ failure.

~Mikayla