The honeybees are out in this warm weather, collecting pollen and nectar. The brood boxes where the queens stays (hopefully and not in the honey supers) are filling up with eggs, brood and food. So the queen excluders were put on a few months ago, this is to stop the queen from moving into the supers and laying eggs in there. You don't want eggs and brood in your honey. The queen excluders allow the worker bees to move into the supers to store the nectar they have collected.
I have split a couple of hive because they have made queen cells, this is to try to stop the old queen from swarming out. Once the colony starts to produce queen cells then they are intent on swarming. You can take out the queen cells and this will give you some time to sort out another hive or nuc box to put the split into. You leave the old queen in the original hive, but none of the queen cells. One of my splits has been named Elder, they were moved to a new apiary site 0n 8th of June. This will be my second 'adopt a hive' which you can find on the shop page.
Adopt a Hive, Elder.