All rooms were kept scrupulously clean. Archaeologists identified very little rubbish in the buildings, finding middens outside the ruins, with sewage and food waste, as well as significant amounts of ash from burning wood, reeds and animal dung. In good weather, many daily activities may also have taken place on the rooftops, which may have formed a plaza. In later periods, large communal ovens appear to have been built on these rooftops. Over time, houses were renewed by partial demolition and rebuilding on a foundation of rubble, which was how the mound was gradually built up. As many as eighteen levels of settlement have been uncovered.