The nucleus method

Almost all beekeeping associations – and most books – teach Pagdens’ artificial swarm as the recommended method of swarm control. It is tried and tested and reasonably dependable. However it can be a bit tricky to grasp for inexperienced beekeepers.

At least part of the problem is you have two hives that look the same, one on the original site, one adjacent. Conducted properly, the adjacent hive is moved to the other side of the original a week or so into the process.

Teaching this in a poorly lit, draughty church hall in late January, facing the audience with the inevitable confusion over left and right, and getting ‘new’ and ‘old’ hives mixed up, often bamboozles the beginner 1. Or the instructor 😉

Here’s an alternative … the nucleus method of swarm control.

There she goes ...

There she goes …

General principles

This method is simplicity itself. When the colony looks as though it’s preparing to swarm you remove the queen, some stores and some bees into a nucleus hive.

This keeps the queen safe in case things go awry with the original colony.

You then return a week later and remove all but one queen cell in the original colony. The virgin queen emerges, mates, returns and starts laying.

A month or so after starting the original colony is headed by a new queen and you have a ‘spare’ building up in the nucleus box. You can overwinter this, sell it, give it away or – after removing the queen – unite it back with the original hive.

And that’s it … I said it was simple 🙂

Here is a more complete account.

Equipment needed

It goes without saying that the nucleus method of swarm control needs a nucleus (nuc) hive 2. Any sort of 5 frame nuc is suitable. Nucs are incredibly useful, so they are a good investment. If you’re buying one for the first time get polystyrene as they’re lighter, better insulated and much better for overwintering bees in. I’ve reviewed poly nucs a few years ago. There are even more makes to choose from now.

I’d recommend not using a two frame nuc as there’s not really enough room for stores and colony expansion 3.

Two frame nuc box

Two frame nuc box … a bit too small for the nucleus method of swarm control (but usable at a pinch)

In addition to the nuc you’ll need five frames that are compatible with your nuc and hive. Ideally, one or two of these should be drawn comb, but don’t worry if you just have foundation. A dummy board can also be useful. Like nucs, you can almost never have too many dummy boards.

Honey bee development

To properly understand honey bee swarm control you really need to understand the timing of the development cycle of queen bees.

Honey bee development

Honey bee development

Queen cells have a characteristic appearance. Unlike the horizontally-oriented worker cells, larvae destined to become queens hatch from eggs laid in vertically-oriented queen cells. After three days as eggs and a further five days of larval development the queen cell is sealed.

A colony will usually swarm on or soon after 4 the queen cells are sealed.

~3 day old queen cell ...

~3 day old queen cell …

This is why it is recommended that colony inspections are conducted at seven day intervals. If the colony is thinking of swarming you’ll find an unsealed cell (because there were none last week when you inspected and they take 8 days to be sealed) and you can immediately start swarm control.

Day 1 – Making up the queenright nucleus colony

If you find one or more unsealed queen cells at a routine inspection … don’t panic. You’re prepared, you’ve done your homework and you have the necessary equipment.

  1. Stuff the entrance of a nucleus hive with grass and place it near the colony 5.
  2. Remove one of the outer frames from the colony (you’ve probably already done this to give yourself room for the inspection) as this should have a good amounts of sealed and unsealed stores.
  3. Check again that the queen isn’t on this frame of stores (unlikely) and that it doesn’t contain any queen cells (again unlikely).
  4. Gently transfer the frame of stores plus all the adhering bees to the nucleus box.
  5. Continue the inspection and find the queen. Be gentle, don’t rush, don’t use too much smoke.
  6. Ideally you want the queen on a frame with some sealed and emerging brood. If you are lucky you’ll find her on a suitable frame.
  7. Gently transfer the queen and the frame she is on to the nucleus box. It is very important that this frame has no queen cells on it. Check very carefully. Destroy any you find.
  8. Your nuc colony is now queenright and has two frames of bees. Push the frames against the side wall of the nuc box, leaving a wide gap.
  9. Into this gap shake a further two frames of bees. Foragers are likely to leave the nuc and return to the original hive. You do not want the box to be short of young bees. If in doubt shake a further frame of bees into the gap in the nuc 6.
  10. Add a frame of drawn comb if you have it then fill the box with foundation. Add a dummy board if needed. Gently place the crownboard and roof on the nuc, secure everything with a strap and turn your attention to the colony.


  • The purpose of this exercise is to establish a small colony with stores, a laying queen, space to lay and sufficient bees to support her and the brood being reared. Remember stores, queen, bees, space and no queen cells you won’t go wrong.
  • You will usually find the queen on a frame with eggs and young larvae. It’s very important that this frame does not have any queen cells on it.
  • Ideally you want the queen on a frame of emerging brood. This offers a number of advantages
    • The young bees will immediately strengthen the population supporting the queen
    • The vacated cells can be used by the queen to lay eggs (so reducing the need for drawn comb, or for the bees to build new comb)
    • The nuc colony will go through a period with no sealed brood and you can take advantage of this for Varroa management if needed (I’ll deal with this in another post)
    • It’s unlikely (due to the age of the other brood) to have a queen cell on it
  • One of the most common problems encountered with this method of swarm control is making up (or ending up) with a nuc that is not strong enough. A weak nuc will be unable to defend itself against robbing or wasps. There’s very little chance of weakening the original hive too much.
  • One way to avoid losing foragers from the nuc is to move it to an out apiary more than 3 miles from the original hive.
  • If you do leave the nuc in the same apiary check it a couple of days later. The bees should have chewed their way out through the dried grass. If they haven’t, pull a bit out at the corner of the entrance to encourage them to fly.

Day 1 – Preparing with the queenless colony

  1. Inspect every frame in the colony. Destroy all large queen cells 7. Anything that looks like the queen cell in the picture above should be destroyed. The idea here is to only leave queen cells containing very small larvae.
  2. Mark the frames containing these remaining selected queen cells using a drawing pin or pen.
  3. Push the frames together, add two frames of foundation, add the crownboard and close up the colony.
Here's one I prepared earlier

Here’s one I prepared earlier

One week later – Ensuring the queenless colony does not swarm

The timing and thoroughness of this inspection is important. Don’t do it earlier. Or later. Don’t rush it and don’t leave more than one queen cell.

  1. Inspect the colony and look for queen cells on the frames you marked a week earlier. These had very young larvae in them then and so will now be sealed 8.
  2. Select one queen cell to keep. Just one. Which one? Choose one that is large, well-shaped and has a sculptured exterior.
  3. Destroy all the other queen cells on this frame. All of them! If you need to remove the bees to see the frame better either brush them off gently or blow gently on them. Do not shake the bees off the frame as this might damage the developing queen.
  4. Gently return the frame with the selected queen cell to the box.
  5. Inspect all other frames in the colony (not just the ones you marked last week) and destroy all of the queen cells you find.
  6. You can shake the bees off these other frames to be sure of finding all other queen cells.
  7. Remember that some queen cells will be unsealed 9 … destroy them all.
  8. Return all the frames to the colony. Close it up and leave it for at least two weeks before inspecting again (see below).
Sealed queen cell ...

Sealed queen cell …


  • The purpose of this return visit is to leave the colony with only a single queen cell.
  • Because you removed the queen a week ago there are no other suitably aged young larvae or eggs for the colony to rear queens from. Therefore, the colony cannot produce multiple casts (swarms headed by virgin queens).
  • The nucleus method of swarm control often leaves the queenless colony very strong 10, if you leave more than one queen cell the colony may produce casts.
  • What if the queen gets lost on a mating flight? Shouldn’t I leave two queen cells? Just to be on the safe side? No. If there’s a problem with the queen getting mated you’ve still got the old queen tucked away safely in the nuc box.
  • Queen cells that are large, well shaped and sculptured have received a lot of attention from the workers and so presumably contain a well-fed and good quality queen 11.
  • Don’t be tempted to inspect the colony in less than two weeks. Ideally leave them for three weeks. If you inspect too early there’s a chance that the queen may not have had a chance to mate and start laying (so the point of inspecting is missed) or – worse – that she returns from her mating flight as you have the box open and is then confused or lost.
  • Don’t meddle! Look for pollen being taken into the colony.
  • Have patience. Bees have been around for a few million years. They would not be this successful if they weren’t pretty good at getting queens mated …
  • Finally, particularly if the weather is poor, check the nuc as well. Ensure that it has sufficient stores. With reduced numbers of bees there’s a chance they could starve if the bees cannot forage (in which case the queen in the main colony is going to struggle to get out and mate as well).

Everynuc …

Pros and cons of the nucleus method of swarm control

With the exception of vertical splits almost all of my swarm control uses this nucleus method 12. I particularly like the nucleus method because I have lots of nuc boxes ( 🙂 ) and because it leaves manageable single-entrance hives rather than double height, multiple entrance stacks.

Almost all of the foraging bees are left with the original colony so the nectar-gathering capacity is not significantly reduced.

I almost never use the Pagden artificial swarm, largely because it ties up too much equipment.


  1. Limited amount of extra equipment needed – five frames and a nuc box … both of which are useful anyway.
  2. The old queen is kept safe and out of the way.
  3. Simple to implement, with just two visits at fixed times.
  4. Reasonably easy to understand the manipulations involved.
  5. No heavy lifting.
  6. You generate a nucleus colony to give away or to build up for overwintering.


  1. You need to find the queen.
  2. You need to find all the queen cells and use your judgement as to their age and quality.
  3. Unless you remove the nuc to an out apiary there’s a good chance lots of the bees will return to the original hive. Make sure you add enough at the start and be prepared to add more if you check the nuc after a day or two and find it heavily depleted.
  4. If you don’t want to make increase the nuc is a little more difficult to unite back with the original colony 13.

Give it a go … what could possibly go wrong?



  1. And so it’s tricky to remember when faced with half a dozen queen cells during an inspection on a hot May afternoon …
  2. Except it doesn’t … you can make the queenright nuc up in a full hive, but use a dummy board to restrict their space. This isn’t ideal as the bees have lots of empty space to heat.
  3. You can and I have, but the queenright colony risks getting overcrowded quickly, or – if the weather turns inclement – running out of stores.
  4. The weather influences this … poor weather can delay swarming, but not queen cell development. Consequently, as soon as the weather improves many hives will swarm and all hell breaks loose!
  5. If you intend to move the nuc to an out apiary more than 3 miles away just seal the entrance for travel – see notes below.
  6. To preferentially add young bees you can gently shake the frame above the original hive to displace the flying bees, then firmly shake the adhering young bees into the nuc box. If you do it this way you’ll often have to shake three frames into the nuc.
  7. Lots of books or websites use this phrase, but rarely say how to destroy the cell. Simply squish it flat between your thumb and forefinger, or tear it out with the corner of the hive tool.
  8. Check the development diagram further up the page for confirmation of this timing.
  9. These were started a few days after you removed the queen so are less well developed.
  10. Particularly if some of the flying bees return from the nuc.
  11. I don’t actually think there’s compelling scientific evidence that supports this conclusion but it seems to make more sense than choosing a oddly shaped or stunted cell!
  12. This is the method I use for all colonies in the bee shed where vertical splits are not an option.
  13. I usually do this using newspaper. Having removed the queen from the nuc I place an empty brood box on the original colony and transfer the nuc frame-by-frame into it. I then fill the spare space with a fat dummy, or simply squeeze the frames up with a dummy board.

35 thoughts on “The nucleus method

  1. Jonny Lavin

    Mr Apiarist, thank you for a definitive and simple to understand increase scenario. I’ve read, literally, 20 or more differing methods all stating they’re the best. I’ve even bought Horsley and Snelgrove boards in the meantime as i approach my first split. I will use this one with confidence as i have a nuc box also. I enjoy all your writings and look forward to your next blog. Thank you again sir.

    1. David Post author

      Hi Jonny
      I’m not claiming this is the best, just that it’s straightforward and reasonably foolproof if followed properly (remove all but one QC!). Horsley and Snelgrove split boards work as well, but there’s more to remember. Choosing the “best” method involves trying several and finding one that works for you, your bees and beekeeping.
      Pleased you enjoy the writing.
      Have a good season.

  2. Gary Thomas


    Started beekeeping last April, found queen cells in August (and yes, as a new beekeeper, I panicked!) but used exactly the method you described. I even, as it happens, bought a Thorne’s EveryNuc to replace the travel box I had to initially put the old queen and brood in). I now have a strong colony in the nuc that I’m about to move into their own, brand new hive whilst the original hive, with the new queen, is also doing well.

    The nucleus process is well described in BBKA Leaflet 003.

    1. David Post author

      Thanks for the reference to the BBKA leaflet Gary … living in Scotland I’ve let my membership lapse and belong to the Scottish BKA instead.
      Pleased you got the method to work for you.

  3. Alan Riach

    The danger of the Nucleus method of swarm control
    The danger is simple – if you accidently leave more than one queen cell in the mother colony (and bees are so good at hiding queen cells, especially from inexperienced beekeepers), then you have produced a swarming machine. Pagden with all its imperfections is more likely to safely leave you with the mother colony and a new queen & hopefully a productive artificial swarm. The main drawback of Pagden is that the artificial swarm colony may still sometimes decide to swarm – putting a queen excluder under the artificial swarm brood box for a week helps. You can also carry out Pagden without finding the queen by shaking everything into the artificial swarm brood box, putting the shaken clean brood in a box above the super(s) & queen excluder, let the nurses re-occupy it overnight and then remove it to the new site.
    In summary if you are going to use the Nucleus swarm control method write the following in capital letters on your hive tool “I MUST FIND AND DESTROY ALL QUEEN CELLS EXCEPT ONE”

    1. David Post author

      Hi Alan
      Like everything beekeeping there are lots of ways of achieving the same thing. Most work reasonably well if followed correctly – and your emphasis on destroying all QC’s but one is absolutely correct – but just sometimes the bees decide to confound things by doing something completely different.
      It’s one of the pleasures of beekeeping, a learning experience and intensely frustrating in equal measure!
      See you next weekend at the SBA Microscopy Course.

  4. Calum Grigor

    Or just bleed off enough emerging brood and young bees so they never feel a need to swarm, and use that to raise young queens and nucs for sale?

    1. David Post author

      Hi Calum
      Yes, but slightly more advanced and this was intended as a guide for beginners who were baffled by description of the Pagden method taught in the ‘start beekeeping’ courses this winter. As with everything to do with beekeeping, there’s a myriad of ways of achieving a satisfactory solution (and an equal number of messing it up!). An appreciation of the development cycle of bees and queens, coupled with good observation and record keeping, always helps.
      I hope the season is starting well for you.

      1. Calum

        Hi David,
        I lost one of 39 colonies, disappointed at that. They have started well, but are getting through their stores like nobodies business.

        Found the following link to an excellent book about observation:

        Moderne Imkerpraxis: Völkerpflege und Ablegerbildung by Pohl, Friedrich is also an excellent book – in German only unfortunately. It describes about 15 different methods of making up new colonies with their pros and cons.

        1. David Post author

          Hi Calum
          I’ve 20 going overwinter. All but one are looking OK. The weak one lost a roof in a storm and was then rained on for several days. It will probably be fine (but slow). Nucs are looking particularly good and – like you – they’re all using stores at a remarkable rate. Loads of pollen going in which is always a good sign … and, on that, thank you for the link to the Horst book. I’ve got a copy somewhere and it’s a worthwhile read.
          I’ve just bought a copy of Increase Essentials by Larry Connor at a beekeeping event I was speaking at. It looks as though it might be useful.

  5. Graeme Cox

    Very helpful to me as I’m just starting my first full season, everything went through winter ok and I will need to split😀🐝🐝🐝
    Many thanks

    1. David Post author

      Up here the winter isn’t over yet … it’ll be mid/late April until I’m confident that everything has got through OK (but it’s looking good at the moment).
      Have a good season

  6. Alan Jones

    Hi David,
    I always used to do a Pagden, but after reading Wally Shaws book on swarm control extolling the virtues of the Modified Snelgrove, I have found this easier (you don’t have to find the Queen in a busy hive) and more reliable.

    1. David Post author

      Hi Alan
      I might discuss Snelgrove boards later this year, but Wally has written well about them previously so there’s probably little to add. I prefer the fewer doors of a standard split board as there’s less to confuse me!

      1. Alan Jones

        Hi David
        With the modified Snelgrove there is no boards involved at all! Wally Shaw wrote a article in this months Beecraft explaining using a Snelgrove board and I began to lose the will to live trying to get my head around which doors to open and which to close.

  7. Emily

    Brilliant – I’m going to print this out and leave it ready in one of my hives! Thank you David. Reports of a swarm already in London!

    1. David Post author

      Or leave it in the nuc with frames ‘ready to go’!

      Marked differences in how the spring season is developing across the country at the moment. I was speaking in Cambridge yesterday and it was lovely weather with the OSR just starting to flower. Here it’s cold and overcast, with the daffs out, but little else. It’ll be some time until the autumn-sown OSR starts flowering here.

      Have fun

  8. Archie McLellan

    Thanks for all this, David. I have so much to manage this spring for the first time (fortunately not without excellent help and advice – not least Bob Smith in our association. See his answer to my question in the recent BBKA News. Or not – SBKA for you).

    You lay great stress on patience and not opening the parent hive for 2, ideally 3 weeks. But if I understand you correctly, unless you leave the nuc in an out apiary, the nuc may need restocking – which is a bit disruptive to the parent colony.

    Which presumably means, better to ask around and use an out apiary!

    Thanks as always for your writing.

    1. David Post author

      Hi Archie
      It’s always easier to move the made up nuc to an out-apiary. However, sometimes it’s not an option. If you can’t it’s worth checking there are enough bees in it a couple of days after making it up. My Everynucs have clear plastic crownboards, so I don’t need to expose the tops of the frames. It makes life a lot easier. Here’s one of my overwintering nucs from the first week in January …
      Overwintering 5 frame Everynuc - early January 2019

  9. Dorothie Jones

    Thanks David. Well explained as usual.
    I went over to this method last year as I’m not that big and strong and found all the heaving boxes about with the Pagden exhausting! This is so much quicker and simpler and gives you loads of options about what to do with your nuc afterwards. Also bees continue to store honey in the original box so les loss of production I think.
    Glad to see someone with your experience extolling this method as I have been told by some that this is not a ‘proper’ method of swarm control!!!
    I’ve tried fruitlessly to get around the use of the Snelgrove board but it does my head in….glad I’m not a bee! Seems unnecessarily complicated to my little brain!
    Id like to try your vertical split using a single entrance split board as I don’t have a lot of space so moving upwards rather than sideways makes sense. Not sure about the lifting tho as I work on my own.
    Keep up the great posts and hope it warms up in Scotland soon!

    1. David Post author

      Hi Dorothie
      Not a ‘proper’ method?! Nonsense. Anything that works reproducibly should be an acceptable method of swarm control. Just knocking back queen cells sometimes works (even Ted Hooper has this in his book) but it’s hardly dependable. Vertical splits with a single-entrance split board work well. However, with two entrances (and the same on the bottom box) it’s easier and there’s no reason to turn the hive around one week into the process. I’m going to cover the Demaree method shortly … this keeps the colony together and is therefore even better for honey production.
      It’s slowly but surely warming up and colonies are all looking very good (so far!).

  10. Gael Wilkinson

    Can I just ask please (entering year 2 of beek here!) would you feed the nuc (syrup or candipollen) in this case or leave the workers to forage and feed at the usual time later in the year if necessary?

    thank you

    1. David Post author

      Hello Gael

      You should prepare the queenright nuc with sufficient stores to cope from the outset. With a full frame of stores ‘stolen’ from the original hive, a frame of emerging brood and a couple of extra frames of bees shaken in on top, they should be OK unless there is a very long period of poor weather. Alternatively, if you experience a protracted ‘June gap’ they might need feeding because they will be light on foragers for the first week or two. However, it’s unlikely the mother colony will be thinking of swarming if there’s a dearth of nectar. I very rarely have to feed nucs made up as described for the purpose of swarm control.

      Longer term, with reasonable weather and forage available they should build up strongly and are likely to be ready for a full hive before the season ends. Then they will need feeding properly.

      As with all things beekeeping … you need to learn to judge your colonies and relate their weight to the forage available locally (and the weather). There’s no hard and fast rules about any of this 🙂


  11. Ann Cavalli

    Hello David,

    Thank you for describing this method so clearly, I’m currently trying this method on two of my hives. Today I wanted to inspect one of the queenless hive to chose the one queen cell and destroy the rest but the weather was too cold to open the hive.

    You stress the timing of this inspection… “The timing and thoroughness of this inspection is important. Don’t do it earlier. Or later. Don’t rush it and don’t leave more than one queen cell”. I’m a new beekeeper so forgive me if these are stupid questions …. What risks am I running by not doing the inspection today? If the queen is in the nuc, and there are no queen cell(s) mature enough to emerge, are they likely to swarm? Thanks so much for sharing your knowledge.

    1. David Post author

      Hello Ann

      The really important point is to not do this too early … to do so risks leaving eggs (within 3 days of there being no queen) or young larvae (perhaps another 2-3 days) from which the colony can rear another queen after your visit. By leaving the visit until 7 days after making up the nuc there is nothing suitable for them use, so whatever cell or cells you decide to leave will be the queen they get.

      A day or two later isn’t a problem. However, if you leave it too long there’s a risk that a new queen might have been started from an older larva and that she will emerge well ahead of the expected time. For example, let’s assume they selected a 2+ day old larva to make a queen from. The queen will emerge 16 days after the egg was laid i.e. in about 10-11 days time.

      This means you’ve got 2-3 days grace. Ample time for the weather to improve and for you to check them.

      The reality is that they probably will not choose an old larva. After all, immediately after the queen is removed they’ve got lots of choice and should choose a much younger one. But it’s better to be safe than sorry.

      I’m going to write about the cells to leave as soon as I find some time … but the safest thing is to leave one good queen cell.

      Have fun

      1. Ann Cavalli

        Thank you David, that really helps. Yes, please do write on selecting the best queen cell 🙏

        And, so far so good with my nucleus method swarm management, thanks again David.

      2. Tim

        Ah that eases my mind! I have a colony from which I have taken a nuc with a queen and my 7 days to go and remove “all but one” is up today and the weather is foul. It will be tomorrow too.
        I can get in there on day 9 judging by the forecast. I suspect I have a little more time in hand as I removed all queen cells (I hope!), not even one with an egg in. They have to start from scratch.

        Talk about a productive colony – 1 split, 1 nuc and 2 (collected) swarms and they were revving up for the off again despite having space, so another nuc! If only they would concentrate on the honey.

        1. David Post author

          Hello Tim

          Some bees seem to concentrate on making bees not honey. I prefer it the other way round – the single brood box topped with four supers 😉 I have two or three colonies at the moment that are on a single brood box, have not shown any inclination to swarm this year and are piling in the nectar. But, of course, they’re not all like that. I have others, double brood boxes absolutely bursting with bees, topped with a pathetically lightweight super. All in the same apiary.

          Of course, knowing my luck, the single brooded colonies are just fantastic robbers 🙁


          1. Tim

            As a follow up, I went back to the prolific brood and a half queenless parent colony, expecting to find a few queen cells to squish.
            54 squished. Some frames with 15 +
            Well, I hope it was 55!

      3. Dorothie

        Interesting. I’ve always been told and read to go back in at 5 days. Not sure why this advice is given as presumably this could still leave 2 day old larvae which could still be a risk? If you leave it 7 days and they’ve already used a larva (although why would they?) you’re too late!! Catch 22?

        Still loving the blog btw

        1. David Post author

          Hi Dorothie

          I think the main thing is to return late enough that there are no larvae left young enough for them to use … and at that stage reduce the cells to 1. If they’ve already started one on an older larva it might be one of the cells you knock back.

          Delighted you’re still enjoying the writing … probably about time I started thinking what to do for Friday 🙁


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