In Lord of the Flies, what does Piggy suggest they can do with their hair?

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http://www.sparknotes.com/lit/flies/

In Lord of the Flies, Piggy suggests that they can use their hair to make a sort of makeshift diary or record their experiences on the island. To find this answer, you can read the novel Lord of the Flies, written by William Golding. The relevant passage where Piggy suggests this idea can be found in Chapter 2, titled "Fire on the Mountain".