Select part of the hive for more information:
The Queen excluder is a device of either a slotted zinc sheet or wire rods.
The width of the slots or between the wires is too small for the Queen to pass but the workers can get through. The effect is that all the eggs and hence the brood is below the excluder.
Any boxes with frames placed above the excluder will consist of honey which the beekeeper can remove as necessary.