What effect does the jungle have on the boys?

Remember-

The boys crash landed on the island when going home from school, and instead of going home, (or wherever they're going) they crashed landed on the island and in the end, the police found out, a school of stranded boys were lost and had to get home. I'm pretty sure that was a scary experience. They are trying to get themselves out of the Coral Island because so far, two people have died...two young boys. The book that William Golding wrote signifies the pig's head, in which Jack Merridew killed. That's the symbol of Lord of the Flies. But then the police asked Ralph, if any survivors were alive, including himself (Ralph). And Ralph answered yes, but two boys are dead. Hopefully that'll give you some idea about your question.