What metaphors are used in The Fifth Child by Doris Lessing?

Harriet and her experiences of motherhood can be seen as a primary manifestation of the work's thematic and/or metaphoric contemplation of the evolution of British society, and perhaps even of society as a whole, over the period of the mid-Sixties to the midEighties. Specifically, her cherished traditional ideas of home and family are almost entirely destroyed by the arrival of the self-indulgent, violent, animalistic Ben.