A queen excluder is a device used in beekeeping to control the movement of the queen bee within a hive. It is typically a flat screen or grid that allows worker bees to pass through but prevents the larger queen from escaping. This helps beekeepers manage the hive more effectively, ensuring that the queen remains in the brood chamber where she can lay eggs. By using a queen excluder, beekeepers can also encourage honey production in the upper honey supers. This separation allows the worker bees to store honey above the excluder while keeping the queen focused on reproduction below, ultimately benefiting both the bees and the beekeeper.