A friend shared this photo with me just now. A swarm this size is known as a “prime swarm” – the first of the season from a colony that is really booming in numbers. They depart the old hive with the original queen to find a new place to setup a colony.
A prime swarm is the best type to catch – the sheer number of bees, and the fact the queen is already well established laying means that they get off to the quickest start possible.
I’m waiting to hear if these bees are still available… fingers crossed!
Added 3 days later – sadly this lead didn’t amount to anything. Hopefully they are settled comfortably in a new home somewhere.