A colleague from our work group has managed to make a video of a very important behavior of his small cell bees. They recognize the danger posed by the Varroa mites, they grap them, bite them and then take them away.
a sensational video:
The behavior of active Varroa defense occurs mainly in small cell bees. Here we explain why.
This is a Buckfast hive. It was accustomed to the small cell size of 4.9 mm recently and is now building this new small cell size well. The hive is completely treatment free and very vital. It has his own honey and is located in Bavaria.
and here a similar video from Finnland in a small cell bee hive: