"Smoke in the Air"
"Something flittered there in front of his mind like a bat's wing, obscuring his idea" (108)
Ralph's moment of doubt is being compared to a bat's wing. He had an important idea that he wanted to convey to the group about the necessity of smoke from the fire on the mountaintop for their rescue, but Ralph's inner child took a second to stop him and look at the fun everyone else was having pushing rocks into the ocean. Ralph is twelve. But his mature- and adult-self recovered quick because their situation on the island is serious. Also, Ralph believes their number-one priority should be making enough smoke to be noticed and rescued from this remote island. Golding uses figurative language here because doubt is a hard thing to visualize. Ralph's second of uncertainty is gone like the breath in between consecutive sentences and can easily be skipped without the visual Golding writes for readers in this sentence.
The image above represents the moment when Ralph has his doubt. His idea is the light behind the hands, trying to get through. The hands represent the bat's wing and/or doubt. The hands block out the idea and become the focus of thought.