The very first kind of house was a cave. It had walls that kept out
harsh winds and prowling animals. It had a ceiling that kept out the
rain. It had a floor on which to sit or curl up and sleep.
In time, people learned to build houses. They used whatever materials
were handy. In dry places, houses were made of mud or clay. Where there
was plenty of wood, people built houses of logs. On grassy plains, they
built houses of dry grass. They learned to use mud and clay to stick
stones together, and they made great towers of stone, such as the cliff
dwellings in the Southwestern United States.
Today, many people still live in houses made of mud, or dry grass, or
logs. Others live in houses made of concrete and steel. But no matter
where we live, or what kind of bouse we live in, our houses are much
like that first cave. They have walls, ceilings, and floors to protect
us from rain, snow, and wind.