Bedouin societies traditionally eschew permanent settlement, preferring portable shelters that allow them the flexibility that their pastoral nomadic way of life requires. Kin-related domestic units or households generally migrate together during the spring and summer months and tend to converge with other households of near kin during the winter months. In the past, Bedouin residence units were composed exclusively of tents ( buyuut ; sing. bayt ). Depending upon the season of the year and, more specifically, the quality of surrounding pastureland, as few as three buyuut, and sometimes as many as fifteen, formed a camping unit. Among some Bedouin groups that spend the winter months in the same place year after year, stone houses ( buyuut hajar ) are also common. In many cases, these winter encampments are only partially deserted during the spring and summer—the very young and the very old are left behind to benefit from government efforts to extend health care and schooling facilities to these settlements. In certain areas of North Africa where transhumance is practiced, the seasonality of movement is somewhat different, although the principle is the same. Structurally, the tent and stone dwellings are alike. Both are rectangular in shape and consist of two—or occasionally three—sections. One section is the women's domain, kitchen, and storeroom. The other section is almost exclusively the domain of men and visitors—where hospitality is extended to guests, clients, and kinsmen alike. Sometimes the Bedouin home includes a third section, where sick or very young animals are given care.