Fecha de publicación: 03/01/1980 Fuente: WIPO "beekeeper" A device for controlling the size of an entrance aperture 11 to a beehive comprises two elongate plates 18, 19 which are pivotally connected at their inner ends and so mounted on the hive that the inner ends may be raised or lowered to vary infinitely the effective size of the aperture. The inner end of one of the plates is also indented at 22 and the plates arranged for relative sliding movement such that when the plates are mutually retracted the aperture is completely closed and when extended a small orifice is formed which permits the passage of a bee but excludes larger animals.