Ambient light in winter/indoor overwintering

There has been some discussion about ambient light and stimulating flights for defecation and foraging as well as temperature tolerances for bees in cooler months. I recently watched a UoG video on indoor overwintering and was wondering if anyone has experimented with restricting light completely and/or blocking the hive entrance(s) during those times of the year when there is absolutely no forage even though the temperature may occasionally be high enough to fly. I am curious if this could conserve resources in the hive.

It’s a great video. I like the idea of keeping the bees in the dark all winter, as in the video. I definitely wouldn’t block the entrance. The bees like to circulate air around their hive & get rid of stale air. In the video, I believe one important feature of the setup is to get rid of stale air out of the room, then replace it with fresh air from outside, which gets heated to 5C.

I didn’t specify but my question was whether the hive could be kept outdoors in complete darkness and have a similar effect. Why do they have to be indoors except to keep the temp just above freezing and keep in dark? And which of those criteria is more critical?

I would never lock bees inside the hive unless I had to. Bees will make cleansing flights on freezing days that you would never expect them to fly. I am sure that @Doug1 and @Tim_Purdie will have seen that. Shutting them in also increases the risk of spreading nosema inside the hive. Let them do their thing. With 250 million years of evolution before we started interfering, I think that they know that they like the entrance open over winter, just in case they want to use it. Just my humble thoughts… :blush:

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In that video it seems the bees don’t poop for months…

But how do you know that your bees will be like their bees? Microclimates have a big impact. If I was a bee, I would want to make my own decisions… :blush:

I like what @Dawn_SD said about cleansing flights. I don’t think it’s critical to keep bees indoors or in darkness. If we relate bees to ourselves: We like to be warm during winter, we like fresh air, we like to be able to go to the toilet at will. Also enough food to sustain us. Let’s face it, the colder we are, the more food we tend to eat.

I like a bee house, such as with @Doug1’s setup. The hive’s are well insulated. Plus the bees have access to the outside would which allows them to circulate air & go to the bathroom at will.

PS. It’s worth noting that the video was put out by a “Research” Center. Therefore with the understanding of the word “research”, it would be fair to say that nothing is conclusive while they are researching different techniques.

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Circulation of air in hive has more to do with regulation of temperature and humidity. Stale air is very different for bees and humans. In experiment by A. Gubin / N. Smoragdova (1946) bees in idle state started to die when oxygen content in air was going below 5%. Without noticeable harm bees were able to live in atmosphere with up to 9% of carbon dioxide in it. Bees are able to slow down their metabolism and survive such conditions and, as a result, consume less food.
Practical application of this data was a possibility to post 4-6 frames splits with 1.2 kg of bees and queen and 2-3 kg capped honey but without brood in boxes that did not have a purposely constructed vents. However in presence of brood bees cannot slow down their metabolism because they have to lift temperature to 32-36°C which without ventilation causes death of brood and often bees.
Since real life hives are not really airtight, it does not make much difference if entrance is open or closed in a wintering hive in terms of air composition.

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I’m in a sub-tropical climate. I’ve never kept bees in a harsh winter region, however it goes against my logical thinking to close an entrance during long harsh winters.

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Oh, normally nobody would. But it is mainly to reduce humidity in hives.

Here is a photo from winter storage. As you can see entrances are opened a bit.

Here is a photo of exhaust fan @Doug1 published. Amount of moisture coming from the storage is quite noticeable.


There is a series of very interesting historical videos illustrating skep beekeeping in Europe and in one of those videos it shows the beekeeper attaching a winter light deflector over the skep entrance…to keep out direct sunlight but not restrict the bees mobility. So your question of the effects of light on wintered colonies has been on beekeepers’ minds for some time:

With regards to the link you referenced from the University of Guelph, Ontario, Canada there is a lot of accurate information there… and there is a video series made by that institute that are well worth watching for the cold climate beekeeper. Our experience of low winter feed consumption is similar being about 17lbs/hive rather than the stated 11 lbs/hive…but hive population could be the reason behind this.

If the conditions are perfect, it’s been our experience that honey bees can endure comfortably 4 to 5 months of flightless activity…after that they become very anxious and populations decrease dramatically. By “perfect conditions” I mean proper ventilation, temperature, feed supply, total darkness (in the case of indoor wintering), lack of disease and parasites, and optimum queen/worker age.

In my area, beekeepers never block bottom entrances completely and sometimes give upper entrances. In the darkened beehouse, the bottom entrances are left open as well as screened bottom boards being used. All winter long those spent bees have the option of leaving the hive through the front entrance or through the screened bottom board (back entrance) to die on the floor… where from time to time they are swepped up and tossed outside. Dying bees dropping from the winter cluster that cannot evacuate the hive can plug the entrance creating a buildup of moisture resulting in moldy combs and a rotting mass of dead bees in the spring…a real mess…ventilation is so important.

Here are beehives wintered outside in my area…ventilation is dealt with in these four packs by very small upper entrances.

upper entrances for wintering

Very true.

Correct…in the photo above, when the spring temperatures increase, the bees will turn that white snow to a brown color…not only are the bees relieved, but so is the beekeeper…the timing of this flight is so important to the success of the colony…they can now bring in water and start brood rearing at an elevated level.

We leave those entrances through the beehouse walls open as long as we can in the fall but when winter sets in, the entrances through the wall are plugged with insulation…but the actual entrances on the bottom board area are wide open to the inside of the beehouse. If it warms up during the winter enough for bee flight and there is a film of water on the snow, we pull out the wall entrance plugs and let them fly…but ready to plug the entrances again if cold weather is in store…which is the norm. Bees die when they land on dry, cold, snow.


Hi @Doug1,

In you setup, there is nothing that connects hive entrances and though the wall entrance like a tunnel? And if not, how big is the gap between hive and the wall if any?

Our hives sit on a standard bottom board…which includes the landing platform that extends out from the brood box wall about 2" (5cm) so the hive body is 2" from the wall…so the hive population overflows into that section and even build a bit of comb there in the summer but it’s not a problem. That 2" landing platform lines up in elevation with the flight tunnel through the wall. Hives from nearby hives co-mingle and the whole inside of the bldg act as one super-hive…this photo… that is 1970’s vintage… shows the phenomenon best. This “master” neighboring beekeeper stimulated his hives after the first cleansing flight in the spring with the subsequent result…still winter outside as hinted by the coat the child is wearing. He peaked in colony numbers inside at 200 hives…each having there own entrance through the wall…and averaged 7 or more 2lb packages of bees.

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averaged 7 splits per colony? Is that over the course of one spring period? And is that done mostly to prevent swarming?

Yes that would be over the course of one spring period and he would have brought in California mated queens to head his splits/packages as well as requeening the original wintered queen. In our area, a young queen in the colony almost eliminates the instinct to swarm.