I closed down my hive entrances for winter, only leaving one hole open but with hardware cloth over it as a mouse gaurd. I was taking a close look at the entrances the other day and noticed my New World Carniolan bees have started propolizing their entrance to reduce it more but the Buckfast bees haven't. The Buckfast bees are from MS and are perhaps not cold acclimated but the NWC hive also is in front of the Buckfast one and perhaps acts like a windbreak for it. I wasn't closing off the single hole any more because I figured they needed to be able to vent the humidity out of the hive.

Has anyone else noticed their bees reducing their entrance with propolis? The rest of both hives are well propolized closed otherwise.