Weep holes or "weeper holes" are small openings left in the outer wall of masonry construction as an outlet for water inside a building to move outside the wall and evaporate. The term was coined by archaeologist C. Leonard Woolley after finding evidence of weep holes in ziggurats. Plastic "weeps" are used in modern masonry construction.
Weep holes are located near the base of masonry structures, particularly brick buildings. Raising the grade above weepholes may allow moisture, snakes, insects, and small animals to enter the building. Modern weep holes employ screens, constructed of flexible nylon or plastics. Typically, drain tiles have weep holes, which allow water to enter the tile.