I regularly examine the floors of my hives. The stuff which falls out of the hive tells a story about what the bees are doing. I always look for Varroa mites. I've found none on the floors of any of my hives for several weeks. I don't know why.
The complicated rearrangement of Hive C left a problem: a gap of a few millimetres where the nucleus box meets the hive body. Every time I approached the hive the bees from inside behaved defensively and I smelled the distinctive alarm pheromone (it's an ester somewhat like Bananas).
This afternoon I returned to the box within a box which contained Colony 13.
It was placed with it's opening almost directly in front of Hive H. How could they not be delighted with the hive and march straight in. Perhaps the bees had other things going on. I decided to act.
I brought a large white board up to the mouth of the hive and bridged it with white paper card. I then carefully removed the inner box and shook it onto the board. To my dismay the bees started going over the edge of the board but not into the mouth of the hive.