Abstract: This invention is a weephole ventilation device that permits evaporation of moisture that would otherwise collect within the wall cavity, while incorporating an insect and rodent barrier. It is designed to be installed after completion of exterior masonry walls. The invention consists of a perforated cover plate, a sealing gasket, a novel anchoring device, and a threaded fastener. The perforated cover plate and sealing gasket sub-assembly form an external barrier to insect, rodent and water penetration, and are held to the masonry wall by the threaded fastener and anchoring device. The threaded fastener passes through the perforated cover plate sub-assembly and tightens into the anchor. The anchor is an innovative device that wedges into rifts or fissures in masonry or other surfaces and provides a surface for the attachment of objects.