Over the last two days, I have noticed bees surging out of two of my hives during the afternoon. Now I check them 5 days ago, and there were no swarm cells or queen cups. The last week has been damp and cold here, with the last two days warmer (17c today), and when the sun hits the hives around 1400 hours, the bees appear to leave the hive in numbers, fly around the front of the hives, and then return after 30 minutes or so.

I have recently started feeding, and the bees are still taking plenty of pollen in, mostly Willowherb but also some bright orange pollen, which I'm not sure about.

Are the bees simply stretching their wings, or could it be orientation flights of new brood? The only time I have seen this behaviour was last year prior to loosing a swarm.

Anyone any thoughts or advice?