The boys on the island are just that - boys. They are children and it is not uncommon for children to fear the dark. On a deeper level, though, all people fear what they cannot see. Fear of the unknown is one of mankind's deepest and most common fears. We can't fight what we can't see. During the day, the boys are more concerned with having fun. They forget about their troubles during the day, for the most part, as they go about the business of being children. Golding relates this to people in general who are blind to the evils of mankind until something catastrophic such as war, occurs. People are like the children, caught up in their day-to-day lives and unable, or unwilling, to seek out and acknowledge the source of trouble until the trouble is upon them. The children feared the beast at night when it was dark, when they couldn't go looking for it because of the dark. People fear trouble when it's too late, too. Golding is suggesting that if people would acknowledge the source of trouble (evil) when it isn't seen and obvious, then people would have a better chance of stopping that source of evil. In chapter 5, this idea is brought to the forefront when the boys discuss the nightmares the littluns are having. Another reason the boys fear the beast at night is the idea of darkness. Golding says that mankind has a darkness within him that is the source of all evil. The beast is alive in this darkness just like the littluns feared the beast in the darkness of night.