Too many bees - Its a great problem to have!
 
I thought I would add my two bobs worth ( to coin a great Australian term).
I have also encountered this phenomenon on my stronger hives in late
spring. I have asked more experienced beekeepers about it and been told
that it is the young house bees which are not yet foraging being kicked out
due to the temperature of the hive. The problem (?) usually dissipates over
a month or so which would support the idea as the bees mature and take to
fields.
 
Enjoy your problem, you are probably the envy of many!
 
Regards to all
 
Paul Roberts
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