As always, Allen Dick's comments on the effects of cold on bees were accurate and worthwhile. Nonetheless, Allen and I approach this subject from very different perspectives. As a personal goal of mine is to get beekeepers to open up their hives with ventilation (winter and summer), I think it is worthwhile to provide a word or two on the difference in perspectives, and why I think (despite Allen's worthwhile experience and thoughts) that beekeepers should adopt the position that 'cold does not hurt bees'. Our perspectives are different because: 1. Allen is in very cold Alberta, Canada, where the winds blow hard all winter. I am near Albany, New York. Here the winters are much colder than most of the US, but not nearly as cold as in Alberta or in Northern Maine (we are colder than southern Maine), Minnesota, or similar places. While we have a fair degree of cold (often enduring a week or more of nightly temperatures of -10 degrees F), and think our westerly winds are bad, we do not nearly have the near-prairie conditions that lead to the kind of winds that Allen gets. 2. I am trying to give advice to the thousands of beekeepers who keep fewer than 25 or so hives and think it is best to speak to 'normal' conditions (whatever those are) rather than the extreme cold conditions faced by a few. From studies by Mark Winston (now at Simon Fraser University in British Columbia, Canada) we know that once bees form a cluster they 'stay put' and do not, as once thought, rotate so that the bees on the outside (where it is very cold) move to the center (where it is 90 degrees F) and bees in the center move to the outside. The only warmth the bees on the outside of the cluster get is that provided by those on the inside...sometimes for several months at a stretch. Marla Spivak at the University of Minnesota, and others, have used probes to measure the interior of beehives, as well as the temperature of clusters. In the dead of winter, they found conditions where bees were surviving with an interior cluster temperature of 90 degrees, an exterior cluster temperature of 50 degrees, and a temperature of -30 degrees just 4 inches from the cluster! Moreover, the bees survived as strong clusters until spring. This is why I make the generalization that 'cold does not hurt bees'. Without exception, every year literally dozens of beekeepers tell me their bees died during the winter, despite ample honey stores and appropriate and timely mite treatments. They want to know why and how to prevent similar deaths in the future. After I have asked all the questions to eliminate disease and lack of honey stores as possibilities, I ask 'when you opened the hive in the spring, what did the interior look like?' By then, I pretty much know the reply I will get 'there was a black soggy mess, mold or fungus was everywhere'. Yuck! Then we go through the drill, with me telling them to open up their hives, particularly with top entrances and them telling me that they are afraid to do so 'because the draft (or cold) will kill their bees'. I have been through this so many times that if I were more intelligent I'd avoid the discussion. But I patiently explain to them that a by-product of the bees maintaining a 90 degree temperature in the center of the cluster is that air is heated. Warm air will gain moisture as it rises upward in the hive. If it hits the top of the hive, where it is cold, that moisture will precipitate (as cold air will not hold as much moisture as warm air), literally causing 'cold rain' to fall onto the bees below. Dry and cold the bees can handle, wet and cold they cannot handle. They die, mold and fungus can survive just fine in 50 degree temperatures, and they feed on the carcasses...yuck! So, if your conditions are at all like those in Alberta, Northern Maine, Minnesota, etc., protect your bees from cold...and still provide a means for the warm moisture-laden air to escape the hive. If your conditions are more like Chicago, Boston, Kansas City, Detroit, or Albany, NY, don't worry about the cold, and be generous about upper ventilation. Hope I can help, Lloyd Lloyd Spear, Owner of Ross Rounds, manufacturer of comb honey equipment for beekeepers and Sundance pollen traps. http://www.rossrounds.com [log in to unmask]