For nearly ten years, I have not put upper entrances in my winter hives. My primary concern for winter was ventilation, but since I began using ventilated quilts on the top and screens on the bottom, I haven’t had any moisture or ventilation problems at all. My hives stayed dry and upper entrances seemed like just an invite for unwanted creatures.
But this year I decided to add candy boards that are designed to go beneath the moisture quilts. For some reason I can’t explain, I decided to put an Imirie shim with a small entrance below the candy boards. This small change has transformed my hives.
How? For all those years, I hardly ever saw my bees in winter. I would see evidence of them, of course—dead carcasses on the landing board, splats of bee poop on the lids during a warm spell, and the ever-present hum of the hive. But since I added the upper entrances, I see bees every day, bees crammed together side-by-side looking out on the world. They remind me of children huddled at the window, wondering why they can’t go outside and play.
Just a few minutes ago, I ran outside and took a few photos. Believe me, it is not bee weather out there—it is dark, rainy, windy, and 40 mildew-laden Fahrenheit degrees.
When I asked myself, why do they gather at the top entrance and not the bottom entrance, the reason became immediately clear: the top entrance is warm while the bottom entrance is cold.
Up is where the warm is
Just think about it. Cold air comes in through the bottom of the hive—through the lower entrance and through the screened bottoms, if you have them. This cold air is warmed to some extent by the bees’ bodies and respiration. As it warms it rises because warm air is lighter than cold air. By the time it gets to the top of the hive, it is much warmer than when it entered.
Remember my posts about temperature in the hive? The warmest place is just above the cluster. It just so happens that the little Imirie entrances are just above and a little outside of the winter cluster. Air exiting the hive at that point is probably downright balmy compared to the air coming in the bottom entrance.
Most likely, other reasons come into play as well. Since the winter cluster tends to travel up toward the honey supply, the bees in winter have a natural tendency to move in that direction. Then too, as the season progresses, the cluster is closer to the upper entrance than to the lower one.
Regardless of the reason, it is entertaining to have a little window on the bees. I love to see them. Who knows, maybe they find me amusing as well.
Honey Bee Suite
I love that photo! I am a first year beekeeper and am fascinated by their behavior. I live in south-central Colorado, at 7,000 feet, in a valley that is protected on all sides by high mountain ranges. We have very low humidity (below 20% year-round), so moisture in the hive is not a problem.
But, the other day, when it was sunny and still, with the sun shining on the hive entrance, I had a few bees flying… and it was just 34° F! A few of them came out, flew around, and then went right back in. But a few flew off. Thankfully, I saw a bee returning to the hive from some unknown distance away. I hope that means they were turning around and getting back before they got too cold to fly.
Wow, 34 is cold for flying.
Hi Rusty, what is the silver above the bees? I showed this post to my bee club, someone was asking if that was a queen excluder? Thanks!
Yes, it is the queen excluder that holds the sugar in place. See “A No-Cook Candy Board“
The bees in the photo above may simply be forager bees whose ocelli are still positively phototactic.
I love this post! I am a first year beekeeper in southwest Ohio with just one hive, and I have followed your instructions and made my own candy board and quilt. Both turned out very nicely, and I put them on my hive last week, with an Imirie shim below the candy board. I’m excited and hopeful for this process, and I’d love to see some bees peeking out the upper entrance once in a while (I’ll definitely be checking now). Thank you!
For the first time, this winter my hives have moisture quilts. Beneath them, I placed an eke to allow space for thick sugar blocks. Oh how I wish there were openings in the ekes! I would love to see my bees peeking out.
I wonder if they are regulating air flow on purpose or by accident? I am using quilts for the first time but put screening above the quilt. I see ice forming on that upper screen and now I have to remove it because in the really cold weather, I know it will freeze over completely. I am thinking of an upper entrance as well but with 1/4 inch hardware cloth over it to keep the shrews out. I just can’t figure out how to make an entrance without taking a chance on sending the bees into a panic during this cold time of the year. I should have made the upper entrance in the bottom part of the quilt box just below the insulation and just above the inner cover. The inner cover sits on the bees and has 4- 2 inch holes in it that are screened over, with the original center hole left unblocked for them to go in between the inner cover and the insulation if they want to. May be a 2 inch space there. I also need to move one hive so it gets better sun and I wonder if anyone has an idea of how to go about that. I planned to move them on a warm day in the 20’s or 30’s and screen them in for 48 hours- not that they would be coming out anyway but I could just see a bunch of them going to the old spot and dying there in the cold.
If they are regulating air flow at all, it is by accident. This makes sense because they sit there on the warmish days. When it gets really cold, they go back inside and cluster. If they were regulating air flow, they would stay there when it got colder.
Interesting about your inner cover. I put my inner cover above the quilt, not below it (if I use it at all). I want the damp air to hit the quilt before it condenses on a hard surface. It seems like the inner cover would make the quilt less effective as a moisture collector, although it would still work as an insulator.
I find moving hives in winter is less traumatic than moving them in warm weather, assuming you don’t have to open them to move them. And locking them up for a few days is a cinch because they mostly keep themselves locked up anyway. As a precaution against mid-winter cleansing flights, you can certainly leave them closed for a few days.
I swear, rusty, you must have some amazing camera, or you must be the world’s best photographer, or a combination of both, because your photos are just fantastic! I try to get decent photos of my girls, but they are always blurry. I get so discouraged. what kind of camera do you use and what other techniques might help me do better?
Also, I see there is no landing board for this upper entrance or a way to close it off – don’t you worry that it might be a problem when the weather warms and robbers are out?
Everything I know about photographing bees is in this post: How I photograph bees. It’s not much, but it might help.
As for the upper entrances, they are in the Imirie shims. Come spring, I can just pull the entire shim. It only takes a second.
Opening up an upper entrance creates a chimney effect, drawing up cold air as warmth escapes. By closing off the upper entrance, the vector of the warm air recirculates, providing a buffer to the cold air and taking moisture down the the sides of the hive.
The chimney effect is also what keeps the hive dry. A bee colony can survive very cold temperatures as long as it is well fed and remains dry. Once the bees get damp, however, no amount of food will keep them alive. It’s very much like spending a night in the woods in dry clothes vs wet clothes: when wet, you can’t control your heat loss.
Living in a very damp climate, I’ve taken many steps to keep the hive dry so, in my case, the upper entrance doesn’t increase the airflow (chimney effect) very much because I have four other screened openings above the brood which does that. I also don’t want any water running down the inside walls of my hive because that keeps the brood chamber too damp and encourages mold growth. For moisture control I use a quilt box that is vented to the outside so it can stay dry as well.
These vents to the outside air do drop the inner temperature, but they control moisture build up and airborne mold spores. But like I said, it is a two-fold issue: if the bees have plenty to eat, the extra effort at keeping the brood nest warm is more than compensated for by a dry and mold-free environment.
What a great photo. I just put my first “no cook” candy boards together and plan on getting them on two of my hives this weekend.
The Broodminder is scheduled to arrive at about the same time so it would be timely to try them both out at the same time.
You had mentioned a site where we could share our Broodminder results. Anything new on that?
I set up a page that you can access from the main menu on the top of any page. It’s called “BroodMinder” and is just a place to leave comments or observations. It’s not very fancy, but short of adding forum software to my site (which I don’t want to do), it is the best I could come up with. No comments on it yet.
My BroodMinder is supposed to come today or tomorrow, but the shipping notice I received had three errors in the address, so we’ll see…
What a great photo! I don’t do moisture quilts, but I do flip over the notched inner cover and put a piece of greenboard insulation on top of that under the telescoping lid. I guess it’s similar to Imirie shim and quilt. I noticed last winter (my first) that the bees hung out on the top bars and occasionally peeked out the notch opening, like yours do. It freaked me out a bit because I thought they were supposed to be clustering. So I guess it’s toasty in there!!
Right above the cluster, it can be quite warm, a fact that lets them wander around a bit and stretch the legs.
Maybe I’ve missed something and if so I apologize but in all the posts you say the candy board and quilt box go on top of the brood chamber. My hives each have honey supers on top for winter. I’m in southern NJ and last winter was very cold and windy. I put candy boards on and the colonies were fine in Spring. Possibly they provided insulation? The bees didn’t use much of the sugar. I’d like to put quilt boxes on – do I put them on over the honey supers?
I am so grateful for all your help!
Right. If you have honey supers on for the bees you don’t need candy boards. And yes, a full honey super provides insulation and also provides some regulation of temperature fluctuations. That is because honey has a high heat capacity. In other words, it takes a lot of heat to warm honey (compared to air) and, conversely, it takes a long time for the honey to lose heat (compared to air). The result is a more steady internal hive temperature.
If you want to add a quilt, put it above the honey supers but under the inner cover (if you are using one).
I am also in CO at around 7700. I see many bees out and about when its freezing out. Not hundreds but maybe 20-30 from each hive. I think its the very low humidity that allows for it. That said, I did have moisture problems last winter with mold on the inner cover. Using Rusty’s quilts now for more insulation and moisture control.
Curious about your hive heater. Its been -27 here at night. And while I wrap the hives in two layers of reflectix and two layers of tarp, extra heat might help too. Thought about using one of those pipe wrap heater cords. Wondering how yours was setup.
Thanks for an interesting post! I’m a first-year beekeeper–so going into my first winter (in North Carolina). I’ve been reading about the pros and cons of upper entrances and have been vacillating about putting an Imrie shim under my candy board and quilt box.
At 7200 feet in the White Mountains of Arizona, our girls come out any time it isn’t windy and is above 40 degrees! I put up a hummingbird feeder about 100 feet away to give them something to fly to for exercise.
“For exercise.” I like that. Do they wear spandex and sweat bands?
This photo is so sweet. Very cute, thanks.
@Catherine: Catherine, for my photos of bees, I use a little Sony point-and-shoot pocket camera. And I get fantastic photos! The camera is a DSC-WX80 and you can still purchase them on Amazon. They originally sold for around $350, but I just bought a second one that was brand new, but in an opened box, for $99.
For an example of what the camera will do, just look at the cover photo on our club’s facebook page. Central Colorado Beekeepers Association. (There are so many bee pages on fb you have to spell it exactly right to find it.)
I like this camera for three reasons (besides price): 1) As you’ll see from that photo, its macro focusing is stellar. 2) I like how the built-in software in the camera processes the image. 3) At 16 megapixels you can really enlarge a photo (to zoom way in) and it will still be sharp.
@cosri: Where in Colorado are you located? I’m in the Upper Arkansas River Valley in the town of Salida. Our humidity here stays below 20% all year round.
I’m a first year beekeeper from Maryland. I am using an insulated candy board ( http://www.brushymountainbeefarm.com/10-Frm-Wintering-Inner-Cover/productinfo/W671/ ) instead of the classic inner cover. One side of the board if filled with hard candy facing directly down sitting on the frames. The other side has a rectangle of insulating material similar to paper mache covered by telescoping outer cover. I opened the top entrance hole which exits through the hard candy directly into the frames.
I’m seeing a very similar picture of bees crowding in the top entrance blocking it with temperatures dropping below freezing outside. It is currently around 20F outside. When I point the temperature laser probe toward the bees crowded in the top entrance, it reads around 45-50F. I am concerned that the crowding bees are blocking the entrance to keep the heat from escaping which leads them to break from the cluster. I am wondering if they would be better off if I would just close the top entrance hole.
I am using a closed screened bottom board in the winter, with greatly reduced classic bottom entrance. The temperatures are expected to drop to as low as 0F in the coldest part of the winter. The relative humidity generally stays under 50% in my area during winter.
Do you think I should cover the top entrance during winter or leave it open?
If you don’t have a top entrance you should at least have ventilation ports. Bees seldom die from cold, but they die quickly if they get wet and cold, so the priority is always to keep them dry.
Also bees don’t try to keep the hive warm; they only try to keep the cluster warm. Bees don’t gather at the upper entrance to keep the heat from escaping; they gather there because it is balmy and warm. And they won’t break cluster to block the entrance, they break cluster because they are warm enough to do so.
Thanks for the knowledge Rusty. I’m going to leave the top entrance open. Great picture btw!
Thanks, Paul. I think they’re so cute.
I have one hive that is now using the upper opening to go in and out to forage instead of the bottom landing board. When I try to minimize the top to force them down they cluster and get lost trying to get back in.
Any ideas to force them to go back down to the bottom boxes.
Just persist. Close the top entrance completely and they will change to the new entrance within a few hours. Once some start fanning from the new location, the rest will follow.
A stroke of luck. I placed a sugar bottle inside the top box to help them through a cold spell and severe wind.
As it turns out the sugar water being on top was warm, started to dribble overnight, and leaked down the inside front wall and onto the bottom landing board.
This morning with the exception of a few stubborn bees flying around on top, most were feeding off the sugar water on the bottom landing board walking in and out. Some were flying out foraging and coming back via the bottom landing pad.
I took the FLIR one infrared sensor and the queen cluster appears to be one box above the bottom box. I think they will get with the program now.
Thanks for the speedy response.
Rusty, can you tell me the approximate size opening on your Imirie shim (above)? I’m thinking about 1-1/2″ wide x about 3/4″ tall? Just estimating by using the bee bodies for a measurement.
The openings on my Imirie shims are 3/4-inch by 3/8-inch.