An interesting day at the hives today, as a new beek I thought I would post it here and see if anyone else had seen this. Today was a great day in the Chicago area for weather, sunny, temps in the mid 60s. I started my hives on Apr 20th with packaged bees on new equipment. The queens were released when I checked 5 days later. An inspection last Tuesday showed several frames with drawn comb and eggs and larva was seen inside each hive. Around 1pm I checked the top feeders and noticed they were a bit low. I removed 20 or so dead bees from the top feeders and added some 1 to 1 with Honey-B-Healthy. The fronts of the hives were busy with bees coming and going, I saw several coming back with pollen. Then around 3pm it appeared as a swarm was starting outside of my 1st hive a ton of bees flying outside the front of the hive. The second hive, which is about 3 feet from the 1st, was normal. I checked back about 15 minutes later and noticed the second hive doing the same as the 1st. I watched closely and did not notice any fighting to indicate robbing, and it seemed to be the same number of bees that were coming and going. The entrance reducer was on the large opening and the bees packed the entrance. 15 more minutes pass again and hive #1 returned to normal activity. 15 additional minutes and the second hive returned to normal activity. So I am trying to figure out what happened. Was it shift change at the factory? Just stretching they wings? Thanks in advance.