Many beekeepers become alarmed this time of year when they realize dead bees are covering the bottom board, piled on the landing board, laying on the outer cover, or scattered across the snow. It looks like hundreds! In fact, it probably is hundreds. Many bees die this time of the year and there are many reasons why.
Winter bees are physiologically different than summer bees. Winter bees have more fat bodies and they are designed to live for many months. In contrast, summer bees live only a few weeks. But by late winter, even these winter bees are nearing the end of their lives. More and more will die as spring approaches. By the time brood rearing is well underway, most of these bees will be gone.
In addition to old age, some bees die because of stressful in-hive situations. These include:
- Starvation: Some bees may not have found sufficient food.
- Disease: Any number of diseases may kill winter bees. These diseases include the viruses carried by varroa mites.
- Parasites: The mites themselves can weaken the bees by sucking their fat bodies and hemolymph.
- Cold: Bees on the outside of the cluster may occasionally die of cold. Or bees taking cleaning flights may not make it back into the hive.
- Dysentery: Bees unable to leave the hive for many, many weeks may succumb to the build-up of waste in their bodies. If waste is excreted inside the hive, it promotes unsanitary conditions that may kill other bees.
During the very coldest part of winter these dead bees may not be apparent to the beekeeper. Most die inside the hive and their bodies drop onto the bottom board. The pile can get quite deep without the beekeeper even noticing it. But as the days get warmer, the bees begin to clean the carcasses out of their living quarters. Depending on the temperature they may dump them on the landing board, or fly them out and drop them on the ground or in the snow. Suddenly you see them everywhere, but in truth, they have been collecting all winter long.
If possible, it is a good idea to clear the bottom board of dead bees. You can scrape them out by removing the entrance reducer and running your hive tool or a stick through the hive entrance and dragging it along the bottom board. You don’t have to remove every bee, just make sure the entrance is open. Beekeepers can lose hives to dysentery if the entrance becomes blocked and the bees cannot get out for cleansing flights. Also, if you are using an entrance reducer, it helps to make sure the opening is at the top—not the bottom—of the reducer.
Dead bees on the outside of the hive this time of year are usually a sign that everything is proceeding according to plan. If your cluster is active and has plenty of food, your colony is probably fine.
Rusty
Honey Bee Suite
RT @HoneyBeeSuite: [New Post] Dead bees all over the place!. What’s wrong with my hive? https://www.honeybeesuite.com/?p=3028 #beekeeping #bees
@HoneyBeeSuite r u sure it’s not just housekeeping on a warm day? There’s natural death that occurs through (cont) http://www.twitlonger.com/show/8mo62e
I’ve noticed many dead varroa mites as well and have to remind myself that this is normal in January.
This is from Michael Bush: “This is the accumulation of many days of mites that can’t get into cells because there is no brood, falling over a period of time. 40 or 50 a day is not considered unusual, so if you have a week’s accumulation of 300 or so that would be pretty normal and within the economic threshold. So probably they don’t need anything.
They may start to rear brood soon if your weather is reasonable as the solstice is now past. So if you want to treat (powder sugar) now might be the best time before they start to rear brood.”
This is from Serge Labesque: “The observation that you describe is a quite normal occurence at this time of year. Here is why: As you know, varroa mites reproduce in sealed cells of bee brood. Normally, they spend only a small amount of time in a phoretic phase (i.e. clinging to adult bees). This is the only time when bees can physically get rid of mites, or the only time when mites can fall to the tray, because mites are exposed then, and not inside sealed cells. Consider that mite population increases exponentially through the season to reach a maximum in the fall. This means that right now is when the number of mites is near its maximum in the hives. So, everything else being equal, you should expect to see many more mites on the trays than at any other time of the year. Furthermore, add to this that it is very likely that there is no brood in your hives right now. This means that the mites have nowhere to hide and to reproduce. So, the mites are all exposed, in the phoretic phase of their life. Consequently, the bees groom the parasites off each other, and the mites fall in large numbers. This period of the year is cleaning time for the hives, at least in respect to the varroa mites. This is why you see so many mites on the tray. Tell yourself that this is a good sign that your bees are at work, getting rid of the mites. Simply hope that they will do a thorough job, and your colonies will do fine in the spring. Do not be surprised to see a few bees with deformed wings in January. This is because the few mites that will be left in the hives will concentrate in the little brood that will be available then. You really need to give a chance to your bees to do the job on their own. Trust them. This is what I do. Understanding the dynamics behind what you observe can help reduce your worries, although we always worry about our bees. Right?
Please consider not treating your colonies with powder sugar or drone brood trapping.”
This all makes sense to me except the last sentence. Why does Serge not recommend the use of powdered sugar or drone trapping? Well, obviously you can’t trap drones now because there aren’t any, but what is his argument against these practices in general? It seems to me that letting the bees “do the job on their own” is a little like letting your cats or your cows loose in the woods to see how they fare. The conditions here now are not the conditions that European honey bees evolved under and letting them fend for themselves borders on cruelty. I don’t believe in using pesticides, but a little mechanical help seems fair enough. Whether we like the idea or not, honey bee are now livestock. We have so modified them and modified their environment that the odds are overwhelmingly against them surviving without help.
Rusty,
Serge was one of my first mentors 18 years ago. He is a fantastic teacher. As time went by, I differed in my beekeeping ideals from him. He did not believe in winter feeding, which I do. He is a believer in survival of the fittest. I tried all natural ways of keeping bees without chemicals. Two years ago I gave into oxalic and apigard treatments. My survival rates have been so much better. I believe that MAN has made it harder on the bees through mono crops, pesticides, climate change and pollination. Therefore, MAN has to help the bees as gently as possible. According to UC Davis, powdered sugar treatments are not effective. I used to do them weekly. I believe that using powdered sugar on the open frames desiccates the open brood and should only be sifted on the tops of frames. After watching the bees in an observation hive for years, I noticed that their grooming increased with use of powdered sugar! My guess is that Serge feels powdered sugar treatment is interfering.
Kathy Cox
I thought about lopping that last sentence out, but keeping it in is an example of “Ask 2 beekeepers a question and get 3+ answers” isn’t it? And I wanted to hear your thoughts, too. We’ve been torn b/n the “help them out because they need it” philosophy, and the “let the bees be bees” school of thought. Is there a happy middle ground? Now that we’re taking care of someone else’s bees, I really don’t know how to approach the hive. While winter seems endless, I feel like I’m running out of time to decide how we treat (or not treat) this colony of bees.
HB,
It’s just another opinion, of course, but to me the happy medium is helping the bees with mites without using commercial pesticides. Personally, I use a combination of screened bottoms, drone trapping, grease patties, essential oils, powdered sugar, and queen sequestering (to break the brood cycle.) I have never, ever not-even-once used any of the commercial acaricides. My mite drops are not especially high, although I do see deformed-wing virus on occasion.
Just as organic farmers have certain “tools” they use to accomplish their goals, natural and organic beekeepers use “tools” as well. But breeders who are trying to raise survivor stock let their bees go it alone. Unfortunately, they often lose just about everything. But they knew that going in, and I believe their work will eventually benefit the rest of us. I appreciate what they do. But that is not my particular mission.
I am enamored by honey bees and enthralled by wild bees as well. I want to raise awareness about both kinds through my site (soon to be two sites.) I believe in organic farming and natural beekeeping and I’m aghast at what our federal government thinks it’s okay for humans to eat–namely systemic pesticides and genetically-modified organisms. So, in short, my personal mission is to spread the word on these topics and issues. I’m not in a position time-wise or financially to raise survivor stock and select for resistant bees. We all can’t do everything, and that means I have to treat my bees for mites in ways that fall within my belief system.
In regard to two beekeepers and three answers, I say what I always say. I believe there are many ways to accomplish the same thing. What is right for one person may not be right for another, and what is right at one point in time might not be right at another point in time–even for the same person. To decide what is right is highly dependent on your ultimate goal, your resources, and your system of beliefs. We are all in a position to learn from each other and that is a good thing.
Once you settle on your ultimate goal, you will know what to do. You are smart, articulate, and sensitive to the issues. I, for one, am very glad you are a beekeeper–you represent us well.
“Also, if you are using an entrance reducer, it helps to make sure the opening is at the top—not the bottom—of the reducer.”
I think I understand that now. I made my own mouse-proof entrance reducers, but the openings are flat against the bottom boards. Melted snow over the past few weeks has clogged the openings. All the dead bees, I assume, would have clogged them up too. If I get a really warm day, I might pull them out, flip them and clear out some of the dead bees. That could be a few weeks from now (our winter is really just getting started).
Phillip,
I don’t think I could bear “winter just getting started.” I am so ready for spring. On the other hand, I miss snow. We had about 15 minutes of snow this year. So sad.
What about a ton of dead worker bees during the first 2 weeks of October? The Carnolian hive has a ton in front, but is very busy bringing in pollen. The Italian hive isn’t doing anything: no pollen going in and haven’t been taking the syrup, but there aren’t very many dead bees in front of that hive.
I too have a hive with a lot of dead bees (several hundred) on the screened bottom board (went clear down and removed the brood super and cleaned the screened bottom board) as well as several on the entrance outside of the reducer. I could not see any mites when I checked the white board. It looked like only several hundred bees were left in the hive and I could not locate the queen (which is not unusual, I have a hard time finding her). Just after Christmas I checked and this hive was not strong but looked like it should make it through the winter, it still had a goodly number of bees and honey stores.
Two questions:
1. What could have killed the bees?
2. Should I try re-queening this hive or combining with the strong hive next to it (if so what should the procedure)?
Your help would be greatly appreciated.
Frank
Frank,
Remember, there will always be a certain amount of dead bees. Some bees die every day. If the weather is good, the other bees cart the bodies away. If not, the bodies are allowed to pile up.
If the remaining colony is really as small as you say, and there is lots of food remaining, my first thought is mites. Seeing mites (or not) doesn’t make much difference. They don’t like to be seen and do a good job of hiding.
My first question to you would be when and how did you last treat for mites? Mite-riddled colonies often collapse during late fall/ early winter, so the timing is about right too.
When you get a chance, look at the empty brood combs and see if there are any white dots inside the cells. If so, that is a sure sign of mites. If you can’t find the queen, it could be the hive went queenless and that is the cause of its demise.
You can combine the colonies with a piece of newspaper between them. If you can’t find the queen, combine with a piece of newspaper and a queen excluder. Put some slits in the newspaper. If the small colony goes down and unites with the larger one, you should be able to find and pinch the weak queen and then you can take out the excluder.
Requeening a hive with only a few hundred bees is pointless. Just cut your losses and try to save the remaining bees.
Hi Rusty,
I just checked my hives today because my bees were out doing cleansing flights even though it was 29 degrees, but it was sunny. Two hives are doing great. One hive was dead. It appears it was too weak and the cluster died due to cold. My question is, there are frames with sealed brood, what should I do with those?
Thank you,
Laurie
Laurie,
As long as the colony didn’t die of a disease, you can put the box containing the frames on top of another colony and they will dispose of the dead brood once it warms up a bit. You can freeze the frames first if you think they contain moth or beetle eggs.
Some people let chickens or wild birds eat the larvae, but unless the frames are protected they will also attract larger creatures.
You can also clean out dead larvae with a garden hose. Very messy. I always get splashed in the face with rotting larvae when I do this.
I vote for letting the bees do it.
What do I do with the dead bees that that I brush out from the bottom board? Let them decompose? I don’t have chickens to eat them (yet, that’s this year’s project).
Cali,
You can just toss them in the grass, but it is best to do it a distance away from your hive because a pile of decomposing bees can attract predators such as skunks and opossums, and you don’t want them hanging around your colony.
I was recently given my first hive by a friend. He wrapped the entire hive in plastic garbage bags for the transporting. When I opened it on the other end, there were a LOT of dead bees. I swept most of them out of the top super but I fear that they’re all through the brood box too. Could they have suffocated? Will they clean the bodies out? Or should I go in and do it? Help!!
Dave,
It sounds to me like they may have overheated and/or suffocated. How long were they in plastic? Plastic doesn’t breathe but it acts like a greenhouse, intensifying the heat.
If the hive is strong enough to recover, they will take care of the dead bodies by themselves. Just be sure the entrances are not blocked with bodies so they can freely come and go.
Also, Dave, let us know if they made it. That is a really sad story.
What about lots of dead bees in August?
I have tons of bees crawling and dying in front of their hive. There were a few starting a few days ago, and tons the last couple of days. The ground for about eight feet in front of the hive is carpeted with them. They aren’t all drones or anything, and their wings look ok. There seems to be lots of bees in the hive still. And they have two full boxes of brood/honey. My other hive is fine. Any ideas what is going on? Thanks!
Becca,
To me it sounds like a pesticide kill. Of course, without testing you cannot know for sure. But hundreds or thousands of dead bees outside of an otherwise healthy hive often means the bees got into something, but they lived long enough to get home. Another clue is the nearby unaffected hive. Because of the waggle dance, different colonies forage in different places, so one could be poisoned while the other is not. A third clue is the speed. Dead bees due to a pesticide usually pile up faster than dead bees due to an illness.
That said, this is the wrong season for most pesticide applications. But homeowners often do not follow best practices when it comes to pesticides, and someone may have sprayed flowers to get rid of all the bees, creatures they consider a nuisance.
Obviously, without seeing or testing I can only guess, but that’s what it sounds like. I’ve had it happen before just like that.
Thanks Rusty,
That was my hunch, but I’m a new beekeeper and haven’t seen a lot of things yet. The bees coming out of the hive often sort of tumble out and some fly off but some just fumble around on the ground drunkenly. Hopefully the rest of the hive can survive! Is there anything I might be able to do to help them?
Thanks again!
Becca,
If it was due to pesticide, there isn’t anything you can do. Very sad.
I’ve had a similar die off that happened in October. I think they got into something. My two hives had similar die offs. There are still bees inside, but much less. Does the die off eventually stop? Can I add a nuc to each hive in the spring? Thanks
David,
If you think it was a pesticide loss, it may stop. Most of the pesticides act quickly and then degrade. There are some that persist in the hive and may affect the brood. But if it appears to have leveled off since October, you are probably okay. The colonies may rebound themselves by spring, but you can add nucs if you want to.
Rusty, I enjoy reading your emails regularly. Very informative. I am new to bee keeping and purchased a nuc in April. Hive exceeding my expectations this past summer. Started with the first super and ended up with 3 in the fall with thousands of bees and almost all the frames with honey.. I opened up my hive today as it was 50 outside and I saw no activity.. Well, to my surprise I only found a couple hundred bees left and they were all dead.. I have a lot of capped honey frames left and it’s been a relatively mild winter.. What happened to the numbers of bees and why did they die? I feel like I just lost my dog.
Chris,
My first guess is Varroa mites. Did you treat for mites in any way? See Absconding bees or death by Varroa?
I am a first year beekeeper or rather a first year bee “observer”. I went to several state sponsored classes, books, Youtube, etc.., but nothing beats hands on experience, hence I am writing this hopefully for some info from you pros !
I noticed about a double handful of dead bees under one of my hive boxes. I have two hives, one Russian the other Italian and it is under the Russians. I installed these 2 nucs about 3 weeks ago. Everything seemed to be going well with the 2 notable exceptions. I was into the hive 2 days ago & nothing seemed out of the ordinary, I had put on another brood box to both hives as the bottom ones were about 75% full however I killed a hive mite crawling on the edge under the inner cover. The second thing I noticed was a strong odor coming from the hive (maybe the dead bees inside?) I don’t smell it now though. I sure don’t want to lose a hive, especially this early. I have enjoyed this SO much and the bees have humbled me and made me appreciate them far more than ever and have taught me so much about them & life itself. Hey, I even use them as examples when I preach !
I sure hope they aren’t all dying. Any ideas of what I did wrong, need to do or should have done? Thanks to all in advance for taking out of your time to help ! Blessings !
Tony,
First about dead bees: an adult honey bee in spring and summer lives four to six weeks. A normal full-size hive loses about 1000 bees per day. A nuc will lose fewer because there are fewer bees. So maybe three or four hundred per day. A few handfuls over a few weeks is less than nothing. More troubling is the smell. The bees should be hauling out the dead and they should not be accumulating inside. A “dead” smell is often associated with American Foulbrood disease. If it has gone away, it is probably unimportant, but if it persists you should test for AFB.
Ma’am,
We had a warm stretch here in Southwest Ohio this past week (55 degrees) that happily coincided with the silver maple bloom–so many bees working them that there was a constant buzzing audible when standing under the trees. Lots of foragers returning to my two hives with pollen, and I took this opportunity to open up the hives. Found a good amount of hard sugar remaining in the mountain camp rims, but I added more hard sugar cakes and a pollen patty to each, figuring the bees would burn a lot of calories foraging, and most trees are still a long way from blooming here.
When the warm spell hit, there was the expected hive cleanout–lots of dead bees hauled out. Here’s what worries me, though: overnight following the warm day on which I opened my hives, cold and snow returned, and in the morning there was a carpet of dead bees on the screen of my stronger hive. I scooped them out with a wire, and the next day (today), there was a fresh carpet. I’m only a third year beekeeper, but I did not observe any abnormalities in the dead bees–no tongues sticking out, misshapen wings, no mites visible, even between segments.
Based on the timing, and the fact that it’s only one hive, I’m trying to figure out if I could have poisoned them somehow. I did not have the pollen patties stored in the freezer, but they were in an unheated shed all winter, and smelled normal. I dribbled a few drops of Honey-B-Healthy on the new sugar cakes, which I know is an off-label use–perhaps when concentrated it is harmful? I did spray a dormant copper spray that day on my small orchard, but there is of course nothing blooming there. I’m a farmer by trade and besides dormant sprays on orchards, I can’t imagine anyone spraying anything so early.
I apologize if this is not the proper place for such a question. Thank you for any thoughts, and thanks for all your work on this wonderful resource. I’m old-fashioned and usually avoid looking to the internet, but the quality of your writing and curating keeps me coming back.
Regards,
Jason
Jason,
You lose over a 1000 bees per day in summer, only a couple hundred per day in winter. The post “Dead bees in winter” explains the numbers.
I have three hives and it has been very hot this last week and I notice a large beard on the hives, even into the late evening. Well tonight I didn’t see the beard on one hive and I noticed a Yellow Jacket carrying off a dead bee. Didn’t think to much of it at first and then saw another. On closer inspection I noticed hundreds of dead bees on the ground around the hive. I am talking a 2’x 4′ area just covered in dead bees and there were a handful of yellow jackets hauling off dead bees. I have a robbing screens on all of my hives and while I have had robbing yellow jackets in past years it didn’t cause a massive pile of dead bees. I also didn’t see any trying to get into the hive, they were only collecting dead bees so as much as I hate those thing I don’t think that they are to blame.
I do not live in an agricultural area, the closest large scale farming is probably a good 8 miles away or more. I have a few neighbors with gardens and orchards, but nothing big, not even very many lawns, lots of weeds. There isn’t much in bloom in the gardens yet, no one really has flower gardens but me and I don’t use any pesticides. So while I am thinking a pesticide poisoning I just can’t imagine something in bloom right now that would need to be treated that would cause this kind of sudden die off. For that many bees to have been exposed I am thinking a large number of flowers that were sprayed. Is my thinking logical or can a few bees bring it back to the hive and cause a die off that way?
Thanks for any insight you can give me.
Barbara
Barbara,
You’re right that it sounds like a pesticide kill. It only takes one sprayed bush, even if it’s a couple of miles away, to cause that kind of damage. And yes, they can bring it back into the hive.
Farmers don’t generally make the mistake of spraying things in flower, but a homeowner will spray anything at anytime.
The mites do not suck the hemolymph from the bees. (Parasites. The mites themselves can weaken the bees by sucking their hemolymph.) Refer to the amazing work done by Dr. Samuel Ramsey here in Maryland showing that the mites on bees and larvae actually are draining the fat bodies. See link below:
https://www.youtube.com/watch?v=Fyfyj-2O47Q
Perhaps at our level we as of yet cannot do anything with this but to support research to find a method to use this info to destroy the destructor. But it is important to have the correct info on your site now that the truth is out. Thank you for all your great work in educating all beekeepers.
DH
Douglas,
You are correct. However, this post was written many years before those findings were made. I cannot change history.
Thanks so much for this article. I was a math, computer science, and engineering teacher for 30 years so I’ve dealt with some steep learning curves. Taking care of my first hive has been one of the steepest curves I’ve dealt with and it seems simple mistakes can kill SO MANY bees!
I thought that the bees might be pushing dead bees in front of the entrance to keep out the cold. (I live in Ohio.). I really appreciated your suggestions to:
1. Use the hive tool to clean out the bottom board.
2. Turn the entrance reducer opening to the top of the stick.
These moves are very simple and I can see the possible benefits.
I couldn’t believe the number of bees that I got out of the bottom of the hive! I spread them out on a tray and in a couple days I will examine them for Varroa mites. This examination will help me evaluate my method of treatment.
I did have a couple girls fly out of the hive as I finished up and they said to say, “Thanks!”
Hi,
We have only started beekeeping this spring and have noticed a lot of dead bees stuck in the queen excluder.
Also someone has mentioned we might have a drone laying queen as we have a lot of drone cells in the super above the brood box. We think maybe the queen escaped into this area during investigations as there are no larvae cells in the brood box now.
Kind regards
Sandra
Sandra,
Without knowing where you live, I can’t give a very good answer. However, as to the queen excluder, what is “a lot” of dead bees? A few dozen? Normal. A few hundred? Not normal. A few thousand? Way not normal.
The second question really depends on the season and since I don’t know if you are in Australia or North America, I can’t say.
Hi Rusty,
I live in Bellevue, ID, and in my first couple years of beekeeping. In January we had a big wind storm and because I was going to work in the dark and coming home in the dark I did not see that one of my telescoping covers had blown off and had probably been off for at least three days. I will never make the mistake again of not putting a weight on the lid. Those three days at night our temperatures were below freezing. There is no way the hive survived. To compare, we have had several warm days and I have seen much bee activity in the hive next to it for cleansing flights and not a single bee out of the hive that had the cover blow off. My question is, should I clean this dead hive now or wait for spring? I don’t want to create an opportunity for pests to develop.
I appreciate any feedback. Thanks!
TJ
TJ,
I would clean up soon so you don’t have to deal with heaps of mold later on.