I don't have a recommendation but I do have empathy. Mine were back-filling the brood's nest before I noticed - even though I had plenty of supers on - obeying the 80 complete, add another box rule - they kept filling the brood's nest. They then swarmed. I made sure there was fresh foundation in the brood boxes (it's all I have) 8 days later, they swarmed again.

Mine were from new packages installed late April.

 

the backfilling of the brood nest usually happens prior to swarming. they will move that nectar up once the new queen is laying, no need to do anything.

 

A strong hive will back fill until they have a new queen or lost there queen.How many brood boxes are on this hive, and how many frames of capped brood in the hive?

 

If they are on a good flow it's an opportunity to get some of your foundation drawn out.
I would take out some of the capped honey frames and replace with foundation.

By the time they draw the foundation you should have a laying queen and when she starts egglaying that will expand the brood nest and restrict the bees from putting nectar in those cells.

When they start to backfill the brood nest with space available to them in the honey supers it means the queen has stopped laying either because shes failing, preparing to swarm or dead.

If you have hatched cells it means your hive has been preparing to swarm for quite some time, it pays to check your hive for swarm cells more regularly by doing that you can take steps to either prevent it from happening or to minimize the impact.

 

They will start to empty the brood nest of nectar when the new queen is ready to mate.

 

Thanks so much everyone!

I am now waiting anxiously to check for eggs in a couple weeks.