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Dead bees in the snow

Here’s a question and photo sent to me by Todd Eaton. Dead bees in the snow are a common concern and I welcome any ideas that we can pass on to Todd and others who are worried about the accumulation of dead bees in winter.

I have never been so worried about the bees. It’s 19 degrees outside, no wind. The past few weeks have been brutal as far as weather and temperature and today “seems” like a warm day. Is this normal for them to do this? I expect one or two but hundreds? I can see they’re taking a cleansing flight but what is making them do it this early? We still have many weeks of sub-zero weather coming.

It is normal for bees on a warmish day to take cleansing flights even in the middle of winter. February is not early to take cleansing flights. In fact, the sooner the better, the more the better.

Sometimes the sun beats down on the hives and warms the interior, especially if the hives are dark-colored as yours are. On occasion, bees can be fooled by the warmth, fly out, and die in the cold. But for the most part they know better and just take quick flights and head back.

Also, bees die every day. In the summertime, about 1000 per day per colony are lost. In the winter, the number is much lower, but there still are many deaths. You don’t say how long it took to accumulate this many, but if it happened over several days I would completely ignore it. Remember that snow affords us an opportunity to see things we usually don’t see, and sometimes those things are surprising.

Nevertheless, a couple things could be going on here. If it really was a warmer than usual day, undertaker bees may have seen an opportunity to rid the hive of dead bodies. If that were the case, it wouldn’t take long to accumulate this many. Just yesterday I was watching bees carry out bodies and drop them four to six feet from the hive, then do a U-turn and go back home.

As I said earlier, some could have been fooled by the warmth of the sun and got caught outside, unable to fly home. On the other hand, some of these bees may have been old and about to expire anyway. Bees often elect to die away from the hive—a mechanism that helps keep the hive clean and free of disease.

More likely, the dead bees you see are a combination of old bees, cold bees, and transported carcasses. It doesn’t seem like an inordinate amount, especially when you divide it by two. (I assume both hives have bees.)

I would not be overly concerned at this point. However, your bees could be experiencing higher than average death rates if they are plagued by mites or honey bee pathogens. Often, when colonies collapse from Varroa mites, the remaining bees persist in removing the dead until the very end. Given just the photo and no other information, it is nearly impossible to say and, at this point, there is nothing you can do but wait for the weather. In the meantime, though, don’t give up hope.

I’m sure other beekeepers have thoughts on this and will share their ideas. In any case, let us know what you find when the time comes.

Rusty
HoneyBeeSuite

Bees-in-the-snow-Todd-2015-02-17
Dead bees accumulating in the snow near two hives. © Todd Eaton.

 

Comments

AramF
Reply

Beside the dead bees, I see probability density curves in action. I wonder what the faded dots are. Buried bees from previous days, or mites too optimistic to die riding a dying bee. Probably the former.

Rusty
Reply

Aram,

Faded dots could be bee poop?

Lyn
Reply

I live in Central Florida, so I don’t have the severe winter problems with my bees. But when I see and hear of all the loss to cold and starving I can’t understand it. I’d be putting the hive covers on each hive to shelter it better and feeding all winter. Why don’t people do that?

Rusty
Reply

Lyn,

Everything comes with pluses and minuses. Winter wraps can often cause moisture build up in a hive, especially if it isn’t done properly. Cold and wet is much worse than cold and dry. Also, snow provides an insulating layer, much like an igloo. A good wrap of snow keeps the warmth in and the breezes out, so it’s definitely not all bad. I don’t worry about my colonies nearly as much when they are wrapped in snow; I just make sure the opening is clear and call it good. As for feeding, bees do best on honey. If they have enough honey, they don’t need feed. It’s only when something goes wrong, like a poor nectar season due to extreme weather, that bees need to be fed.

Jason
Reply

I just checked my hives after several days of sub zero weather and a ‘warm’ 22 degree day today. 8 hives and guessing about 500 dead bees on the fresh snow. Some bees look freshly dead, others dead for sometime before being dropped on the snow. Remember one thing. They didn’t get there on their own, still activity in the hive. This time of year any activity is a good thing.

Rusty
Reply

Jason,

I agree with that. Activity usually means the bees are doing what they should be doing.

harold meinster
Reply

I have been having dead bees since January. I believe I just lost my most strongest hive to the bone chilling cold.

This hive started winter with more bees that I expected. I got concerned that I started to feed them honey. It appears that they did not make it when I looked in this morning with the temp close to 40 degrees.

My other hive, far smaller still has active bees. But if the winter continues they too may succumb.

Peeking in, it would appear that they had food, but they were too cold to move to it. What a shame to lose such a product hive so close to spring.

Rusty
Reply

Harold,

That is a shame, but it’s the time of year when it happens the most. I hope your second one makes it.

Phillip
Reply

It looks like the usual scattering of dead bees in the snow. But here’s a little anecdotal info for what it’s worth, which probably isn’t much: I noticed a few hundred dead bees outside one of my hives about a month ago, worker bees cleaning out the dead, cleansing flights, lots of bees flying around. But it was on a cold day when none of the bees in any of my other hives were active. I knew something unusual was happening but I wasn’t in a position to do much about it. A couple of weeks later the colony was dead from a shrew having gotten inside the hive. It feasted on the bees until the cluster was too small to stay warm.

Rusty
Reply

Phillip,

That is fascinating, and it might answer a question I’ve been having. I have one colony that puts bee body parts on the landing board. Heads, thoraxes, legs . . . never whole bees. All my other hives put out whole bees. I was thinking it might be a mouse or some kind of an insect predator, but it’s too cold to go in and look. The really odd thing is it happened two years in a row in the same hive. The colony made it through the winter last year, and I didn’t see anything weird about it when I checked last spring. What do you think?

Phillip
Reply

I haven’t had time to do any deep research on this yet, but you might have a shrew in your hive. I’ll cut the chase. Here’s a photo of what I’m fairly certain are signs of shrew in one of my hives:

https://flic.kr/p/qPnuY2

Decapitated bees, body parts scattered all over, and what appears to be shrew poop. I found exactly these signs in the hive I mentioned in my previous comment. I’ve heard from other Newfoundland beekeepers recently who’ve said they’ve experienced loses because of shrews. Here’s an informative piece on shrews that seems to be copied-and-pasted from another source (but anyway):

http://goo.gl/U9DZuP

A few highlights:

Shrews can easily squeeze through half-inch mesh. A 1/4-inch mesh will keep them out. Supposedly 3/8-inch is small enough, too, though I’m not ready to believe that just yet.

“They [the shrews] feed on colonies by grabbing a bee from the outside of the cluster where it’s colder. Bees on the outside of the cluster are sluggish and unable to defend themselves against the shrew invader. The shrew will then carry its prize away from the cluster and move to the bottom of the frame or sometimes near the top under the inner cover. There it will remove the head and tunnel into the thorax using its pointed snout to consume the contents.”

Shrews don’t nest in the hive like mice. “The primary food source in the hive for mice is pollen and honey; however shrews will only target the honey bees themselves.”

I’ve seen signs of shrews in a few of my hives. There’s not much I can do about it now. But next year I’ll probably use 1/4-inch mesh on all the entrances once the bees stop bringing in pollen.

Rusty
Reply

Phillip,

You’re a genius. This is exactly what I have. I kept seeing hollow bees without heads and was wondering what did that. And also, the feces was on the landing board, so I thought it wasn’t a mouse because mice usually don’t go in and out in the winter. But it makes sense that I had them last year and this year in the same hive.

But here’s my question: Do they just run in, grab a bee and run out? If I add a screen, how do I know if I’m locking them in or out? It’s too cold to take the hive apart and look. Where do they go when they’re not eating? Are they nocturnal or diurnal? Would a queen excluder keep them out?

Phillip, I’ve been puzzling over this for two years and never thought of shrews. You are my hero.

Phillip

Those are all very good questions. I have some ideas but really I don’t know. Do they go inside the hive, chow down on a few bees and then leave? If I was a shrew and had to eat 125% of my body weight every day to stay alive and found a big ball of bees ripe for the picking, I’d never leave. Clearly more research is required.

Rusty

Well, Phillip, it looks like I’m going into research mode. I want to know everything there is to know about shrews in beehives. Maybe we can do a joint post or something. Meanwhile, I need to know how to get them out of that hive . . . I’ve been thinking the colony looked smaller lately.

Rusty
Reply

Now I wish I had taken pictures instead of just flicking the parts away everyday.

Phillip

I have an idea: You can do all the homework, write the post about shrews and eventually I’ll write a similar post and quote you on the salient points. (I’m on a writing hiatus until I find a new place to live / keep my bees away from humans.)

I watched a robust colony dwindle down to nothing over the past couple months. I brought the hive back home to do a postmortem and a shrew popped out between some frames when I got down to the last deep.

I know there’s a shrew in at least one of my other hives and I suspect the cluster it getting smaller by the day. If I had a nice warm day, I’d risk it and tear the hive apart and scare the shrew away and put on some quarter-inch mesh. But that’s not likely to happen any time soon. My other thought is to tilt up the top deep in my hive, quickly check to see if I can spot the shrew and poke it away with a stick. Then put a queen excluder underneath the deep so the shrew can’t get through it and hope for the best. Stand by…

I just looked up something I wrote last year. Check it out:

http://mudsongs.org/a-mouse-in-the-hive-or-no-honey-left-in-the-hive/

That’s a shrew in one of my hives (I thought it was a vole). I just read the whole thing. It’s all starting to make sense now. Damn.

Jared
Reply

I had a hive cluster in the top brood box, and I didn’t realize it until they starved to death in December with an entire brood box of honey below them. Prior to me finding them starved, I saw a lot of dead bees in the snow radiating from the hive like this picture. I think they chanced freezing to death to forage. Or knew they were going to die, so removed themselves from the hive.

Rusty
Reply

Thanks, Jared. That’s something that Todd could do now: peek in the top and see if they have food, or else just give them some hard candy in case.

Andy
Reply

This is all fascinating I’m starting a hive this spring and I live in MA so this helps with what I might see in winters in the future. Thanks

Brian P. Dennis.
Reply

The usual explanation is that snow reflects UV light. If the bees are tempted out, they fly into the snow thinking it is the sky and perish. I don’t know how this fits with the bee’s ability to detect gravity and know which way up it is.

Todd
Reply

Thank you Rusty for explaining this to me. I have only been keeping bees for about 7 months. These are my first two hives. The smaller one is smaller in size due to losing a queen a couple months after getting them. We raised a queen from the larger hive’s brood and got lucky with that. I am a bit worried about the food level on the smaller hive and will have a chance to check this Sunday when the weather gets into the 40’s. I think I’ll make up some candy and place it in both just in case. I did want to clarify though that all the dots around the bees are from the cleansing flights that they were taking. All of those that are shown is from a single day of sun and 19 degrees with no wind.

willowcreekhoney
Reply

I have two hives at the same yard, next to each other. One hive has no or very few dead bees about it, while the other has lots of dead bees about the hive and on the landing board. The property owner, who likes to check up on the bees,a very good steward of the bees, noticed that one hive was active and the other was not. He made the comment that he thought it was funny, the active colony had the most dead bees about it.

I checked these hive a week later and found the active hive very alive, while the other was a dead: dead bees clustered to gether on empty combs. That is why there was no dead bees outside the hive; they where all dead inside! Dead bees outside the hive is not always a bad thing. In the winter, if the hive dies, the bees will still be in the hive. My observation.
Ken

Gary Rondeau
Reply

Rusty, I’m with you and Jason. I would be much more worried if I saw nothing!

Pedro
Reply

Maybe the accumulation is also due to the fact that the scavengers that would normally take away/eat the dead bees are not active/present at this time of the year. The dead bees I see around my hive in the afternoon are never there in the morning, I think mice get them in the evening. If the mice/birds/shrews/spiders were hibernating/migrated the bees would quickly accumulate, I gather.

Greg
Reply

We have hives in Quebec and the dead bees are a good sign of activity inside. We don’t see that many bodies in a day unless the snow has melted for several days. Usually five or so dead bees a day. Also I made special winter covers with a vent hole on top. All winter the access hole at the bottom of the hive must be kept clear of snow so air will flow from bottom to top and move humidity out. The humidity freezes inside the cover then melts on a warm day dripping onto the frames. I see snow at the bottom door and no upper vent on your hives which could be the problem. Good luck, Greg

Emily
Reply

Rusty:

I have one hive since July 2014. I bought a nuc colony. I live in Maine and we have had a brutal winter. Snow (80″ or more with drifts) and temps 0 to the teens. I have not been able to get to the hive. Would you think that I should consider making candy and sneak it into the hive?
Thank You.

Rusty
Reply

Emily,

That is probably a good idea, especially if the temps get up into the 30s. But if they don’t, just have a candy cake ready to slide in there. You’ll need a feeder rim or shallow super so you have room to put it. Have everything ready to do it the first time, so you don’t have to open it twice.

Nancy
Reply

Rusty,

My 2 hives were ok after the 2nd-last bitter cold spell (sugar cakes, moisture quilts and “Bee cozies” of Dow Board). After this latest spell, we’ll see. Crikey, it’s cold.

But the two I look after for the Nature Center in the next county are gone. Well, one had a small cluster, all dead, with honey close by. The other was empty – no brood, no bees, live or dead, not even on the bottom screen. They had honey too.

They were there in October. Would a colony abscond in November, even on a 60-degree day? The dead hive I can understand: we have had some of those vicious “non-diurnal” temperature patterns when it’s warm at sunrise and drops into the 20’s by afternoon. Those days are on the increase with climate change, and I think we could lose more colonies to them.

Thanks for all the info: best wishes for your bees and all your readers’ too.

Nan

Rusty
Reply

Nan,

I don’t know the answer to your question, but I’ve heard this same story repeated dozens of times, mostly in the last two years. I’m trying to learn more. My gut says “No, they won’t” but the evidence seems to say otherwise.

harold meinster
Reply

I had one hive like this last October. no bees, no bodies and sufficient amount of honey.
My only guess is the queen may have had difficulty and they moved to the hive next to them that had a good queen.

Evelyn
Reply

So interesting that I saw this post, just as I was going to google about dead bees in the snow! I also have dead bees in the snow, although not as many. I live in Staten Island New York and have 2 hives facing south, guarded by a south-facing beige garden wall. Besides blocking the north wind, the wall reflects the sun and creates a micro-climate 10 – 15 degrees warmer than the surrounding area. We have been having a rough winter, however there have been days here and there, that have been warmer and my bees have flown. In Todd’s picture, it appears that the same conditions exist. I hope Todd’s, as well as my bees make it through! I will keep you posted on the developments.

Rusty
Reply

Evelyn,

Yes, please do let us know.

harold meinster
Reply

I lost one hive last week and I was concerned that I might lose the other.
I purchased a 12 volt heating pad that slips perfectly under the bottom board screen and catch board. I have a indoor/outdoor electronic thermometer also installed.

Last Sunday it was in the 40’s so I opened up the remaining hive, fed them and covered them up.

This morning the outside temp on Long Island was 1 degree F. The inside cover was 21 degrees and inside (not nucleus) was just above freezing.

Can’t let this one go with out a good try.

Rusty
Reply

Sounds promising, Harold. Be sure to let us know what happens.

Rose
Reply

About the dead bees in the snow, which we are seeing…
Do you think the bright sunshine on a cold winter day tempts them outside, where the COLD drops them into the snow, so they can’t make it back home?

What if I lean something in front of the entrance, to block the sunshine to that area, to keep them from being so tempted (especially if the weather forecast is for warmer weather in a day or two) ?

Rusty
Reply

Rose,

Bright light and warmer temperatures does draw them out, but you want them to go out and take quick cleansing flights: they will be healthier for it. Some of the bees you see in the snow were dropped there by undertakers, some went out to die (which is normal behavior), and some may have died from the cold. But you want your bees to go out whenever possible; I would not block the sunshine.

Marlene
Reply

A lot of dead bees in the snow around our hives here in Canada on the east coast. We are new beekeepers so are keeping a close watch. We had two above freezing days and then back into the deep freeze again with another snow storm on the way. The bees were out flying, cleansing and some dropping in the snow. We have screens for the entrance but they are larger than 1/4″. Hopefully, shrews are not the problem.

Rose
Reply

I have a set of old car floor mats, and a large rubbery floor mat, and some rubber back carpet squares.
Thinking of putting them on top of the snow, on a sunny day, right around the hives.
So if the bees drop, there is some chance (not touching the snow)
they can fly back to the hive. Otherwise it is hari-kari, more or less.

Rusty
Reply

Rose,

Remember that dead bees in the snow is not necessarily a bad thing. Some of those were dead in the hive, and undertakers carried them out and dumped them. Some were old or sick and left the hive to die, which helps keep the rest of the colony healthy. You can’t assume that all dead bees died from exposure to cold air.

Judy
Reply

It’s April and the weather is still pretty cold. I opened my hive and all my bees were dead. I’m not sure of the cause, it may have been the cold or the lack of available food. The bottom 2 deeps were almost empty of food, but the upper 2 shallows were and are filled with honey. I’m new to beekeeping so I’m not sure what I did wrong. Is the honey that is still capped still good to eat?

Rusty
Reply

Judy,

Sometimes bees starve if the honey isn’t near the cluster. Also, did you treat for mites? Varroa mites are still the primary cause of colony death. But yes, the capped honey is still good to eat and it is also good for getting a new colony started.

harold Meinster
Reply

I also had one of my two hives go through till the End of February. Then it was over. My other hive is fine and foraging today.

I had a lot of bees in the lost hive, but they were scattered. They had more than enough food both capped and uncapped.

I did not notice anything out of the ordinary other than freezing to death.

I live on Long Island , NY and the winter was pretty cold. My feeling was that being they were scattered in the hive and not balled together, They must have been working around in the hive and the brutal cold snap caught them of guard before they were able to cluster.

I have no other indication of a problem.

Jeff in the Adirondacks
Reply

O rats. The 1/2″ hardware cloth I am planing to use this winter is not going to keep shrews out. I want the bees to be using the bottom entrance and I always clear the dead bees from inside on the bottom board all winter long because there are so many. Can bees get through 1/4″ mesh ok?

Jeff in the Adirondacks
Reply

Thank you for all the advice! Right now the double screen board sounds good. Just wondering about the move when the weather cools. I am thinking that I’ll put them on top of a 3-deep hive, close them in for 3 days so they will stay put and put their entrance at 90 degrees to the bigger hive. 180* from the main hive entrance below would mean no sun at all on their entrance. I’ll modify the double screen board so I can get access to pull the dead bees out during the winter. I use a flue clean-out tool for that, which belongs to our wood-fired kitchen stove/oven. That is just the thing for that job. (My wife would disagree). Then add a quilt with 3″ of wood shavings and lots of ventilation. Going to check the Betterbee store website and see what they have in the way of mouse guards. I’ll take your suggestion about the 1/4″ mesh if the guards are not able to keep the shrews out but I will make an assembly which cuts the incoming air by about 50% at the landing board but will allow the air to get in across the full width of the hive so there are no dead-air zones hopefully. I also put vestibules on the entrances to keep the ice and snow away from there. Thnaks again…….Jeff

David
Reply

Question.

The other day, I was standing outside and my sister is terrified of bees. She swatted it with her hands and killed it out of mid air, no I don’t promote killing bees but not point of my question 🙂 she left it laying on the ground about 5 feet from us while we talked.

Within 3-5 minutes, another bee showed up, and after a few minutes flew away with the dead bees head it ripped off. A few minutes laters, another bee (possibly the same) returned and took the body part of the dead bee.

I have done much research and can’t find an answer for this? Why?? I wouldn’t have believed it yet I seen it with my own eyes and got pictures. The dead bee was outside, just on the ground. Why would another bee come, mutilate it, take half away and possibly come back to retrieve the other half?

Thank you for any help!!!! I’m so curious!

Rusty
Reply

David,

The scavenger was most likely a wasp and not a bee. Wasps are meat eaters and other insects, including bees, are their primary food source. You will often see them taking insects back to the nest to feed the young.

Bees do not eat meat, instead they eat nectar and pollen. There are thousands of species of both bees and wasps, and they are often difficult to distinguish. But the big difference between them is that wasps are meat-eaters and bees are vegetarians.

Jeff in the Adirondacks
Reply

Rusty

Problem solved with appearance of a crisis. So the big hive produced a queen after it swarmed. I found the cell that the queen came from. She never made it back from a mating flight so the colony is queen less. So I put the weaker/smaller hive hive on top of the now queenless larger/stronger hive which I was going to do anyway before winter, but now with a sheet of newspaper instead of a snelgrove board. Within a couple hours, the hive was going like a 12 cylinder engine with a turbocharger on it. And now the queen that left with her swarm (to make the smaller/weaker hive) is right back where she came from on July 8. I will be making sure that I control the swarming next year. The fall flow is going strong here and the bees in all the hives can best be described as “working at a frantic pace”.

Rusty
Reply

Jeff,

Sounds like it’s all working out. Congratulations.

Scott
Reply

I often see my bees attempting to fly off with the dead bees that are laying on the ground in front of the hive. And, occasionally, they succeed! I can’t find any information about this behavior. Have others experienced it?

Rusty
Reply

Scott,

Absolutely! The theory is that dead bees give off an odor that attracts predators, especially things like wasps. The odor may also attract scavengers such as opossums, so it’s better for the colony if they are not found. By carting away the bodies, the colony limits the build-up of dead bee smell. I’ve seen them carry corpses long distances and it is the strangest sight.

Scott
Reply

That really makes sense. I have been seeing small hornets of some variety feeding off of the bee carcasses.

However, here’s another interesting note: My hive has Varroa mites. Yesterday I saw a bee drag another bee with deformed wings out onto the landing board. The infected bee was trying desperately to get back into the hive and the bee that had dragged it out was preventing it from doing so. The infected bee finally fell off of the landing board. Today, I saw a healthy bee drag an infected (and alive) bee out onto the landing board and then attempt to fly off with it.

That makes me wonder whether the bees are trying to “clean house” of the virus that the Varroa mites carry.

Thoughts?

Rusty
Reply

Scott,

Yup, that’s how they do it. Honey bees have fewer genes that fight disease than some other insects. Lots of scientists believe that honey bees make up for that lack with their hygiene practices. They will force sick and deformed bees out. They can also detect sick or deformed larvae and pupae and pull them out. Even through the cappings, they can detect something wrong and yank that pupa out of there. Sometimes you can see them on the landing board or on the ground. It is also why honey bees use propolis. These plant saps have antibacterial properties that protect plants from diseases. The honey bees collect them and use them to help protect the colony from diseases. So yes, honey bees are fanatics about getting rid of anything that might be a threat to the health of the colony.

Almost forgot, another interesting thing is a bee that has been poisoned, say by insecticide, will realize she is sick and leave the colony and die in the field in order to keep the colony free of whatever is killing her. Honey bees are so cool.

Scott

This is my first year to keep bees and I am completely smitten. They have captured my imagination, my intellect, and my heart.

It is heart-breaking to see the bees with deformed wings. I sure wish we could figure out a way to eradicate the Varroa mites without harming the bees.

Paul
Reply

I really love the oxalic acid vaporizer. A little bit of capital investment but it makes varroa treatments easy. I have two apiaries in southern British Columbia. One has full southern exposure with my house acting as a northern windbreak. The winter losses and rate of honey consumption is less than my other 4 hives, which rest around 600 to 800 feet higher in elevation and southern exposure is blocked partially by treeline. Also need to improve the windbreak. I’ve not lost a hive yet coming out of my 5th winter as a beekeeper, but it has been close at the poorer apiary site. Ive had to scrape out bottom boards plugged with an inch or more of dead bees. Mold present in hives, either from rotting bees or condensation issues. I’ve also thought about the seedling heating pads but think I’m going to move in the direction of a northern windbreak/heat sink at my poorer apiary and see how that fans out.

Jeff in the Adirondacks
Reply

I’ve been cleaning out dead bees from my hives all winter long. I use a special tool to pull them out through the front entrance. We have had temperatures here in the single digits even in April but I think the bees are doing well because of the moisture quilts. I have a BroodMinder inside the hive just below the insulation in the quilt box. I would say that there are 10 to 15,000 dead bees in front of the hives. Each hive. It is 14° today but a couple days ago it was in the 40s and the bees were bringing poplar pollen in. We just got 5 inches of snow today but thanks to the quilts I think the bees are in really good shape.

Rusty
Reply

Jeff,

I use a special tool as well. It’s called a stick 🙂

Jeff in the Adirondacks
Reply

Hi Rusty
LOL. Well, it’s the clean out tool for our wood fired cook stove. My wife lets me know how special it is every time I leave it out at the hives
By not keeping the fire going and not cooking anything. Maybe I should use a stick.

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