A queen excluder is a grid placed in a hive so worker bees can pass but the larger queen cannot. It is a simple tool with a simple job: keep brood out of the honey boxes. This page says what it is and when keepers use it. The name Queen Excluder is a direct home for that topic.
What a queen excluder does
The openings are sized for workers. The queen’s body is larger, so she stays in the brood nest below. Honey can be stored in the boxes above without eggs in the comb. The tool is a sheet of slotted metal or plastic, or a wire grid in a frame.
Why some keepers use one
Harvesting is cleaner if honey frames hold honey, not brood. An excluder is one way to keep those jobs separate. Not every keeper uses one. Some prefer to manage the hive without a barrier and accept extra sorting at harvest.
When it is usually placed — and removed
It goes above the brood box and below the honey supers. It is taken out before winter so the cluster can move with the queen. Whether to use one is a judgment call; this page does not sell a method. If you want the name, it is for sale.
To ask about this name, write inquiries@queenexcluder.com