Why are my bees balling up in feeder

Morning. Well, maybe not where you are! Recently I started using top feeders. Man Lake to be specific. When I went to check how the bees were doing everything looked fine, but I was a little surprised to see bees kind of “balled up” in a ball. The ball of bees was about 2 inches around. This was the case in both top feeders. Anyone else seen this? Any ideas as to what is going on? Thanks. Dale

Hi Dale. I really wish I could give you some advice. You can only follow your local advice.
Here we don’t feed our bees, well, not since I started 6 months ago anyway.
Can’t your bees find any forage at all?

Very hard to comment without a photo. Could it be that a wasp or other pest has found the feeder? Bees will ball those to kill them.

They could be building comb. My bees love to build comb in my Mann lake hive top feeders.