Yesterday I closed off the SBBs, after having them open all summer. After a while, on one hive,I noticed the girls were out fanning - I think they did not like the reduction in ventilation. (I would have pulled it back out, but that particular hive is older equipment, and closing the SBB means unstacking the entire hive and installing a solid bottom board on the stand, and I did not want to do it again.) Does anyone in the northern realms leave the SBB open all winter? I've read articles, but still can't bring myself to do it. Maybe I'll ask for a proper SBB for Christmas. Does anyone recommend a particular kind? I have one of Countryrubes SBBs, and it seems nice. No angled landing board, and it does have nooks and crannies for earwigs and spiders, but is very well built and functional. Any other opinions?