With the exception of a few administrative towns—such as Aizawl, the Mizoram capital; Haka, capital of Chin State; Falam, Tedim, Matupi, and Mindat in Chin State; and the various district administrative towns in Mizoram State—the Chin peoples live in agricultural villages ranging in size from a few dozen to several hundred houses. There are more towns and fewer very small villages in Mizoram now because from 1964 until well into the 1980s Mizoram was insurgent Territory in which the Indian government instituted massive resettlement and village consolidation. Now, as traditionally, the average household has about five persons in it. Villages tend to be situated well up on the hillsides, though some are placed nearer the small streams lower down. Village location has always been a compromise between the need for defensibility and the need for access to water. Houses and villages are oriented according to the possibilities provided by the convoluted slopes. Houses are built on pilings, though in some places one end or the uphill side rests directly on the ground. Traditional houses are built of hand-hewn planks for the most part, though the poorer ones have at least their walls and floors made of split bamboo. The roof is generally thatched with grass, but in parts of northern Chin State there are some slate roofs. Nowadays corrugated iron or aluminum sheeting is used when possible. The traditional floor plan is of one main interior room—or at most two—with its central hearth, a front veranda open in front but covered by a roof gable, and frequently a shallow rear compartment for washing and various sorts of storage, which may have also a latrine hole in its floor. The major limitation on the size of a village is the accessibility of agricultural land. These people are exclusively shifting cultivators: they clear and cultivate a hill slope for one to five years or so, then leave that slope to fallow and clear another forested slope in their territory. The longer a hillside is farmed, the longer it must lie fallow until fit for use again (twenty and more years in some cases), and it is not thought manageable to have to walk more than 12 kilometers or so to one's fields, so that a village's territory extends not much above 10 kilometers from the settlement periphery. An average household can and must cultivate a field of 2 hectares or so. Traditionally, when the population of a village outgrew its effective ability to get access to farm tracts it would move as a whole, or some smaller groups would break off and move away from the parent settlement. Villages might also move because of vulnerability to raids from powerful neighbors, Because of such inauspicious events as epidemics, or simply because a better site was found elsewhere. Since the imperial period villages have been forced to remain stationary, and the increasing pressure of population on the land has resulted in deforestation, erosion, and depleted fertility, as fields have had to be used more years in a row and the fallow periods have been reduced substantially. Fertility also depends upon the ash resulting from the felling and burning of forest on a new hill slope. Thus, the lengthening of the periods of use and the shortening of the fallow periods have combined to lessen the ability of forest to regenerate. Overuse and reduced forest recovery also have led to heavy growth of tough grasses replacing forest growth during fallow periods, and this too has set a severe limit on the system of shifting cultivation as the population has grown.