This is my first hive that I installed in April. I saw a huge frenzy in front of the hive on the first warm day after a cold spell of about 5 days of rain and cool weather (40s at night). I had put in a division board feeder on the top hive body during this spell to get them to draw some comb in the upper hive body, which I put on about a week ago.
I thought it may have been robbing, so I put in the entrance reducer.
I did the old screen trick after dark (covered entrance with screen) and in the morning there were only 4 bees outside the hive. I am hoping this indicates this was not a robbing event and just my bees being busy on a nice warm day after the cold snap. Or more brood hatching out?