The First Time I Had a Shrew in a Beehive But Didn’t Know It

It’s June 2019 as I rewrite this post from December 2013. 2013 was when shrews first got into my hives, but I didn’t know it at the time. I would see all these signs of shrews again during the winter of 2015 when shrews destroyed or catastrophically wrecked havoc on six of my eight colonies.

The conditions seemed perfect for shrews in the winter of 2015. I heard about commercial beekeepers in Prince Edward Island and in New Brunswick who lost up to 80% of their colonies due to shrew predation. Snow was so high at times that it seems the shrews were able to skitter across the deep snow and hop into beehives through the top entrances that didn’t have mouse guards on them. (Who puts mouse guards over the top entrances? Nobody.) Once inside the hives, the shrews would pluck one bee at a time from the edge of the cluster, suck the guts out of the bee’s body and then go back for more, all day long, day after day until the cluster was so small and the bees were so stressed that they were goners before the snow melted. It was a pretty damn devastating situation all around.

A shrew tunnel in the snow. (Next to an earplug for scale.)

Shrews can squeeze through 3/8-inch mouse guards, so page 1 from my anti-shrew playbook is to staple or use push pins to attach 6mm (quarter-inch) mesh over my bottom entrances around the first week of October or whenever I think it’s getting so cold that the bees are beginning to cluster. The mesh might knock some pollen off the bees’ legs, but not enough to concern me. With push pins, I can always temporarily remove the mesh if the bees are having a particularly busy day of foraging. I sometimes cover the top entrances with mesh too just to be extra safe. And it works.

But in the winter of 2013 and 2015, I didn’t have a clue. Here’s how it first played it December 2013:

One of my six colonies either has a mouse in the hive that’s scaring all the bees to the very top of the hive, or the colony is completely starved for honey. Either way it seems like most of the bees (and they’re grumpy) are clustered above the top bars and living entirely off dry sugar I added about a month ago. The bees are so crowded above the top bars, they’re constantly walking in and out around the top entrance. I also noticed many dead bees in the snow in front of the hive:

13-12-23 Hungry Bees in Snow

Not that dead bees in the snow are unusual, but none of the other hives have many dead bees nearby, hardly any. This does not bode well.

When I managed to crack open the inner cover, I saw some sugar over the top bars but couldn’t look closely to determine how much was left because I didn’t want the bees to start pouring out the hive and freeze to death — they were in the pouring-out mode, extremely defensive. I quickly tossed in a big crystallized honey patty and left them alone.

June 2019 Comment: Right off the bat, those were two signs that something wasn’t right. First, the bees were ultra defensive. Some bees switch into that mode during the winter anyway, but any sudden change of behaviour, especially if the behaviour is defensive — that ain’t so good. My usual first thought is, “Something is bothering the bees.” (And that something is sometimes me, messing with the bees too much when I should just leave them alone.) It could be mice chewing around the entrance trying to get in, or maybe a mouse or a shrew actually got in and has stressed the bees. But whatever the cause, stressed bees are defensive bees, then weaker bees, then dead bees. Suddenly defensive bees raises a red flag for me.

The other red flag is more dead bees in the snow outside one hive when all the other hives are clean. Some colonies for various reasons are just more active in the winter than others and finding more dead bees around their hives isn’t necessary the end of the world. But in 2015 when shrews destroyed most of my colonies, the first sign of trouble in all the colonies that eventually died was a large number of dead bees outside the bottom entrance when there were no dead bees outside the other hives.

That behaviour makes sense when I consider the first time a mouse got in one of my hives. It was in the fall and I had a medium super full of wet drawn comb (frames that had been extracted) placed on top of the inner cover so the bees could lick it dry before winter set in. Then one day I found all the bees in the colony stuffed into the honey super. And the bees were ultra defensive. I quick inspection uncovered piles of chewed up slivers of wood and chunks of comb missing from the frames near the back of the hive. A mouse was living in the bottom of the hive and the bees were so stressed, they got as far away from the mouse as they could by moving up through the inner cover hole and stuffing themselves into the empty honey super where they would quickly die from starvation if didn’t kick the mouse out of the hive pronto.

So to recap, highly defensive bees and an unusual number of dead bees outside the hive was the first sign that a shrew (or a mouse) was inside the hive.

What I can’t do: Dismantle the hive and shake the mouse out, if indeed a mouse is in the hive. (I poked around the bottom board with a stick and didn’t find a mouse, but that doesn’t mean one isn’t hiding between the frames.) The risk of chilling and killing the bees is too high, and with most of the bees in a bad mood hanging in a disorganised mass above the top bars, mouse or no mouse, any kind of dismantling of the hive in the middle of the winter is bad news.

June 2019 Comment: Nope. If I was sure that a shrew was inside the hive, I wouldn’t hesitate to tear the hive apart and expose all the bees to cold air if I had to. Bees are much more resilient than most people think. And chances are there’s very little or no brood that would get chilled to death in the winter. Even if I had to remove every frame of bees, exposing them to the cold, and set them up in a new shrew-proof hive, it’s better than leaving them alone with a shrew in the hive.

If a mouse is in the hive (and I can’t do anything about that now anyway) {Wrong! — 2019 me}, I have a feeling it could be game over for the bees. If the bees have run out of honey, I’ll have to do everything I can to keep them alive with sugar, which is something I’ve never had to do so early in the winter. I know some like to think of the solstice as the beginning of the end of the winter, but let’s be realistic. We’re just getting started.

April 5th, 2014: I found a dead shrew in a different hive:

Dead shrew in a hive. (April 5, 2014.)

I noticed the bees had pooped inside the hive all over the top bars a few weeks ago, which for me is a sign that the colony has become queenless and will soon die. Now I know why.

June 2019 Comment: Some would argue that if there’s poop in the hive, the bees are dying from some variant of nosema. A gross amount of poop dripping out of the top entrance, from my understanding, could indicate dysentery or nosema, and poop inside the hive is even worse. But I argue that most colonies have nosema all the time but not enough to hurt them. It’s not until the colony is stressed and made weak by some other factor (for instance, a shrew eating the colony alive) that nosema can rush in and kill them. It’s a classic weakened immunity response brought about by stress. I imagine the queen gets stressed, the warmth and protection of the cluster is shot to hell because the bees are freaking out about the shrew that’s picking them off one by one, the queen dies from the cold or just bad nerves, and all the remaining bees completely lose their reason to live. That’s my literary imagination taking over, but I don’t think it’s too far off from what actually happens.

The hives are still half buried in snow. I probably won’t have a chance to clean up the mess for another two or three weeks. Note to self: Put those mouse guards on earlier.

April 29th, 2014: I didn’t find signs of a mouse in the hive. What I did find was interesting, though. It’s a three-deep hive. The top deep was nearly empty (the bees have been eating raw sugar above the top bars for a few months now). But the middle deep was jam packed full of honey. I’d say at least six of the ten frames were (and are) filled completely with honey, mostly untouched. Only a few frames in the middle of the box had some honey eaten away. The bees were clustering in the top deep for most of the winter — and ignoring a full deep of honey right below them. That makes me think they were scared up by the presence of a mouse, but I didn’t find any mouse droppings or slivers of chewed up wood or any comb eaten away. Strange. I wonder if the bees would have starved if I hadn’t given them sugar. I’ve never seen so much honey in an over-wintered hive before, though this is also the first time I’ve had a three-deep hive going into winter (at least I think it is). You never really know what the bees are going to do.

June 2019 Postscript: It was definitely a shrew.

9 thoughts on “The First Time I Had a Shrew in a Beehive But Didn’t Know It

  1. Try lifting the hive. You will be able to tell how much honey is in it based on whether it is heavy. If there is a mouse, there will usually be a pile of nesting material on the bottom board. Candy boards allow you to put more sugar on the hive at one time, quickly.

    Good luck!

    • I know candy boards are probably the best way to feed the bees over winter, but I’d still rather stick with dry sugar feeding than messing around making a mess brewing up hard candy. I kind of hate cooking up hard candy.

      The situation with this colony is a bit perplexing because I added a full deep of honey to the hive a little over a month ago just before I wrapped it and gave it dry sugar. Not all the frames had capped honey, but still, that deep weighed a tonne. I can’t imagine the bees eating through most of it in a month.

      Perplexing situation #2: I know up close and personal what mouse damage looks like…

      But I haven’t noticed any unusual debris or nesting material on the bottom board. Not yet anyway.

      I’m not sure what to think. I’ll check on the hive again as soon as I get a mild day. I’ll load it up with about 10 pounds of sugar and hope for the best.

  2. Philip, Did your hives not produce enough honey this year to support themselves through the winter? We had a very good year here in Cape Breton. Just curious, why the sugar feeding?

    • Most of the hives seemed to have enough honey, but I didn’t top them up with sugar syrup in the fall, so as a precaution, I gave them the dry sugar early. One of my colonies, a huge colony, starved last winter because I waited too long to check on it…

      I didn’t want to risk that again.

      We had a good summer for bees, too, but most of my colonies were not in top honey-producing condition. None of the colonies were requeened this year (I did try, but one queen was a dud and another queen was rejected). Two of my colonies were started from splits made from swarm cells. Another colony superceded its queen. So all of my colonies had either slower old queens or new queens that took at least a month to mate and begin laying well. As a result, I didn’t get much honey from any of them, though I did enjoy watching the bees more or less manage themselves.

      I don’t really advocate the “let the bees be bees” approach to beekeeping, because there are times when you have to intervene, but my mostly hands-off approach this year was as a close as it gets. It wasn’t much for honey production, but overall the colonies were healthy.

  3. I agree, I don’t go for the “let bees be bees” approach either, because then one would not really be a beekeeper. I am guilty of feeding sugar syrup in the past, but I hope to keep it a thing of the past. Sugar is as bad for bees as it is for us. I always made sure my hives weighed at least 100+ lbs going into winter and never lost a hive to starvation. But last winter for the first time my bees had to contend with mites and that was a disaster. This year I am wintering 3 hives (2 are 3 deeps), no treatments, but they are partially converted to small cell so we will see if they survive. Are you aware of Dee Lusby’s the yahoo group? Very good information on natural beekeeping. Sure do hope your hives make it, it really is depressing when we lose bees. All the best to you in 2014.

  4. It’s good to see the bees made it through the winter, even though there was a vole in the colony.

    Scrape off what you can. The bees will clean the rest.

  5. Mouse in hive? UPDATE: No. More honey than I’ve ever seen in an over-wintered hive before. But no mouse. See the last update at the end of this post for the details.

  6. That’s no vole. That’s a shrew. They are extremely efficient predators that need to eat their own body weight to stay alive. You’re lucky that it died likely to cold or you probably wouldn’t have any bees in that hive.


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