While installing the top feeders today, I took some pictures of the bee clusters:
Here is a close up cluster inside hive #2 (a Langstroth in Sultan)
Cluster seen from outside
The 4 packages have taken residence in their respective hives. No loss, unlike last year (one package absconded).
Those pictures got me thinking. Maybe there is another big advantage of the Warre hive (or any foundationless hive): During the first few weeks after hiving, the bees are allowed to cluster. With foundations, the cluster is broken up. I wonder how that affects the initial development of the colony.