Queen includer” is a term used when a queen excluder is placed in a hive to confine a queen to a particular part of that hive. Probably the greatest use is to place it between the floorboard and the brood box when a swarm is put into a hive to prevent it from absconding, as they will often do, especially if hived on foundation. Once they have decided they will stay there are usually no problems.

A fertile queen in a swarm will usually start laying within 24 hours, so once you see eggs you can remove the queen excluder and you should be O.K. The problems arise when there is a virgin queen in the swarm, as they need to get out to get mated. In general a swarm will issue within a few hours of a virgin queen emerging. They take 5 days to sexually mature, so that is a maximum time the queen excluder should be in place. I only use this system where there is a virgin queen in a swarm, because I clip fertile queens when running them in. I leave the queen excluder there for a maximum of 3 days, less if they are building foundation out well. I know the difference between a fertile and virgin queen, but an inexperienced beekeeper may not, so it may be safer to use a queen excluder than clip her.

It is often suggested a queen includer can be used permanently to prevent a colony from swarming. It may for a time, but a lot of damage can be done to a colony in the meantime, including:-

A small queen may get through an excluder and you will lose the swarm anyway.
If the queen can’t get through the excluder one of the virgin queens might and the colony will swarm.
If the swarm issues, the virgin left behind may not be able to get mated.
Drones are also prevented from getting out and will clog the excluder.
Much of the pollen is brushed off the legs of the worker bees and is wasted. This could cause a nutrition problem.
There are several reasons why a queen may be imprisoned in one part of the hive, but this will usually be under controlled conditions and for a short period.