What metaphors are used in America is in the Heart by Carlos Bulosan?

looking for a better life is an underlying metaphor in the book. Conditions in the rural Philippines are harsh for the peasants. There is hardship, exploitation and subsistence existence. The peasant children have no childhood because they are working in the fields or in the market or home with the parents at an early age. The boys leave their parents' home in their early teens to find work and a better life, trying to escape the harsh and hopeless environment. Their families know and expect this. Carlos' mother tells him several times that he can go and that they are poor. They go from menial job to menial job trying to eke out a living. The parents can't give them a better life in a subsistence farming environment and the parents and children know this.