How do the mother and father let their children know that they are creating an early morning disturbance in the novel, Morning Girl?

Early in the morning, when Morning Girl and Star Boy are grumbling to one another, Father turns on his mat and says, "Ghosts. My house is filled with ghosts. They talk to each other all night. I'll have to build a new house. I'll live there in peace. It will be wonderful." He is gently joking with his noisy children, and Mother plays along with him, saying she will join him in escaping the ghosts who will not allow them their rest. The parents deliver the lesson that the children are disturbing them in a gentle and loving way.