Why do pueblo houses habe no doors n no windows on ground level

Traditional pueblo construction used limestone blocks or large adobe bricks; the latter were made from clay and water and generally measured approximately 8 by 16 inches (20 by 40 centimetres), with a thickness of 4 to 6 inches (10 to 15 centimetres). In the early 21st century, modern construction materials were sometimes used in tandem with adobe, creating stronger and more durable structures. In a typical pueblo building, adobe blocks form the walls of each room as well as a central courtyard; buildings can be up to five stories tall. Usually each floor is set back from the floor below, so that a given building resembles a stepped pyramid. This architectural form enables the roof of each level to serve as a terrace for the level above. Movement between levels was traditionally accomplished by means of wooden ladders, although staircases are now used as well. Ground floor rooms had (and in some cases, continue to have) no ground-level doors; used almost exclusively for storage, primarily of grain, they were traditionally entered through rooftop openings. Most rooms above the ground floor can be entered by doorways from adjoining rooms.