Quote from Sarah Grew "Has anyone got experience with big (huge) observation hives? I am curious about this possibility. Specifically, is it possible to have a self sustaining observation hive. How could the bees form a winter cluster..." Sarah Don't believe rumours that bees can't cluster in an observation hive, they come pretty close... The first time I over wintered an ob hive I was very puzzled because the population would drop than miraculously pick up again! , all in a period of 24 hours. After closer inspection I could see that when the population 'appeared' to fall that actually nearly every cell towards the centre of the colony was occupied with dormant bees. With both sides of the comb occupied like this a large number of bees seemed to disappear. I guess this is actually what bees do in a normal hive as tucked up within a cell with bees on seven sides out of eight has got to be the smart way of doing it. Our house heating system cycling the temperature (bad for bees) caused this pattern to break with the bees sitting on top of the comb when the temperature was higher. Very large observation hives experiences A colleague in my local assoc stared a full size ob hive consisting of a glass box sized about 3 brood boxes in volume. This built up over 3 years to be a very powerful colony with all natural comb with a tree branch embedded within it. This was a great attraction local shows. However we were starting to scratch our head just how we were going to maintain this monster when the whole thing sadly collapsed due to over heating. We'll learn. But difficult maintenance is a factor to consider if this is the sort of thing you have in mind. I run observation hives all year round which are only 2 brood + 1 super frame and the only real attention is: 1/ To keep an eye on their stores especially through the early spring. 2/ They don't over populate 3/ Varroa treatment, like any colony now (uk). 4/ Once a year cleanout usually combined with 2 or 3 above. Cheers Graham