Most Kenyans place great importance on the family and the orthodox values and responsibilities associated with it. Kenyan families tend to be large, and households often include many members of the extended family. Polygyny (the practice of having multiple wives) exists to some extent among all social classes and ethnic groups. Many of Kenya’s rural inhabitants live on small farms; some live in houses made of mud and wooden poles with thatched roofs, while others live in houses of brick or stone with metal roofs. A small number are nomadic farm animal herders, notably some of the Masai people in the south and the Turkana in the north. City dwellers who are wealthy or middle class typically live in modern houses and apartment buildings; many other city dwellers live in shanty towns or other inexpensive quarters.