Wooden frame houses in Germany use wooden frames, bricks for walls, and ceramic roof tiles. Gel houses in Mongolia are portable nomadic dwellings used by herders, with a wool-filled cloth covering over a wooden pole framework. Houses in southern Morocco are made of sun-dried clay bricks mixed with water and molded, then assembled and plastered with clay. Native American tepees were portable cone-shaped tents carried on horses, covered with buffalo hides or canvas, and used for hunting or festivals. Batak houses in Indonesia are stilt houses with ornamental carvings meant to ward off evil, using natural red, white, and black pigments representing the cosmic spheres.