Back filling the brood nest?

[D Coates]

I've got a 5-frame OB hive.  Four of the frames are fully drawn out and have full activity in them (brood, pollen and capped honey).  I occasionally steal frames when they started getting crowded.  The top frame that I put in in June is 75% drawn out.  This top frame has some nectar/honey in it (+/-25% and falling).  I've noticed lately that the bees are pulling the honey out of the upper frame and backfilling the brood nest.  I've never noticed this before in this hive (going into my 3rd year with on OB hive) or other hives.  I check this hive every day via the glass.  The queen is 1.5 years old.  Have others noticed this before?

[BeeMaster2]

It might be that the bees are forcing the Q to slow down her egg laying due to a lack of a food source.
Jim

[BrentX]

Do the bees use a separate area for collecting nectar and beginning the honey transformation, then move the honey to another location for finishing and capping the honey?

I have long suspected this as the bottom box (near the entrance) in my hives is usually packed with nectar, but honey rarely gets capped down there. 

[D Coates]

Do the bees use a separate area for collecting nectar and beginning the honey transformation, then move the honey to another location for finishing and capping the honey?

Not that I am aware of.  The hive entrance in right under the 4th highest deep frame.