bee biology

What is a brood pattern and why does it matter?

Brood pattern on a foundationless frame. Flickr photo by Maja Dumat.

Experienced beekeepers frequently talk about brood pattern. But what is a brood pattern and how do you tell a good one from a bad one?

A brood pattern is nothing more than the place where the queen laid her eggs. Simply put, the brood pattern is the shape of the brood nest. The queen lays her eggs altogether in a group, and the group has a characteristic shape that we call the brood pattern. It is easiest to see when the brood are capped with wax, but an experienced beekeeper can see the pattern even when the brood are in the egg or larval stage.

The capped brood are usually in the center of the frames, and since the cluster is more or less spherical, so is the brood nest. On cold days or nights, the cluster of bees is able to keep all the brood warm since the brood pattern mimics the shape of the cluster.

When you look at one frame you are seeing a slice of the brood nest. Think of a round loaf of bread. If you cut it in parallel slices, the pieces on the outside are smallest. As you get closer to the center of the loaf, the slices get larger and larger. After the largest slice, they begin to get smaller again.

It is the same with your brood pattern. The frames on the edges will have less brood than the frames on the middle, and the very biggest will be in the center. The bees usually store a layer of pollen around the brood nest, and above the pollen–and perhaps to the side of it–they store honey. Drone brood is often found along the bottom or the sides of the worker brood.

A slice (frame) taken from the center of the nest is often described as a rainbow–a layered arc consisting of brood, pollen, and honey. The nest is not always dead center in the middle of the hive, but it may be. Photos of good brood patterns are often so perfect that the beginning beekeeper thinks something is wrong with his bees. I’ve included a photo below that shows a pattern that you’re more likely to see–good, but not picture perfect.

Another important aspect of brood pattern relates to the number of empty cells. Some empty cells are normal and may even be used to warm the brood. But the brood cells should not be random or scattered; cappings should be uniformly brown or tan and not sunken. Too many holes in the pattern may indicate an old or failing queen, or they may indicate disease, or they may indicate a colony not large enough to care for all the brood. It is for these reasons that beekeepers use the overall look of the brood pattern as a measure of colony health.

The photo below shows a foundationless frame, not completely drawn out. The brood nest is skewed toward the front of the hive, but you can see that the pattern is solid with only a few empties. Pollen is stored in the uncapped cells on the perimeter of the brood nest and honey is stored in the upper corners. At the bottom of the brood nest is a spattering of drone cells. Although this frame doesn’t have a textbook pattern, it is obviously from a thriving colony. With a little practice, you will be able to identify a good pattern when you see one.

Honey Bee Suite


  • I find my queens often refuse to lay in the cells containing the wires running through the foundation, so there are diagonal lines of empty cells along the comb. It’s fascinating how fussy the queen is about the cells she lays into, even though she’s laying several hundred eggs a day.

  • Emily, I noticed today in my inspection that there were vertical “stripes” of empty cells, exactly following the wires in the foundation. Pretty cool. Guess I have a fussy queen.

    • It’s probably that those cells are slightly colder because the wire conducts heat to the colder edges of the frame… don’t quote me, that’s just my theory.

  • Hi Again Rusty,

    I hope this is not off topic too much.

    My newish hive of 5 weeks – I only fed for the first week as they stopped being
    interested in 1:1 unless it was right on their landing board – and then it sort of
    seemed they where just keeping things clean … syrup placed anywhere
    else was of no interest…

    They built comb like crazy – 10 frame box – they didn’t like the outside frames
    so much – ended up with a couple of frames in drying nectar , brood frames – nice pattern
    and I’ve been super happy – I’ve not put on a second box yet as I’m trying to get
    bee density high to help keep the small hive beetles away – I have traps etc as well …
    So I guess I have 7 of the frames fully drawn both sides – and less on the remaining
    3 – one of which – outermost- is not really touched.

    I notice today – in amongst my brood they have started to put nectar in some of the comb.
    Just a small number at this time

    So I’m a little worried about the new trend – any ideas what might be motivating the girls
    to do this ?

    Again – just a fantastic site you have created.


    • John,

      Several things. The fact that your bees are building comb like crazy and not taking syrup means they are getting plenty of nectar. You can stop the feeding. But I see trouble ahead. (With that statement, I feel like I need a crystal ball and some funny clothes.)

      Anyway, in an effort to control beetles, you have crowded your bees into the one box, and they are feeling restless. Bees hardly ever like the outside frames, so that is not unusual. But if you are seeing nectar stored in your brood frames, you may be looking at an impending swarm. Seems crazy, I know, but the crowding is getting to them.

      They “think” they don’t have enough space in the current hive for more brood, plus honey and pollen, so by filling some brood cells with nectar they can shrink the brood nest and prevent the queen from laying too many eggs. But with a crowded hive and no place for the queen to lay, they may soon swarm—even though it is a brand new colony.

      Read “Backfilling: the sign of the swarm”; you may have to do some manipulations to avert the swarm, but you have time. But even before you read that post, go give those bees another box. Right now! Go!

      By the way, John, that is a really, really good catch. Most experienced beekeepers would miss that.

      • Rusty,

        I ran out – I put a second on on !!

        I so appreciate your advice and wise words – I understand the pressure
        I’ve put them under now.

        I’ll read your Backfilling now !!

        Thanks !!!

  • Rusty,

    I’m, impatient 🙂

    Not much activity in the top box… a few bees wondering about – not the burst of comb building ( they often do so much in 24 ours ) I was hoping for.

    Would your “Pyramiding: getting bees to move up” post be applicable to
    me as a way of getting things moving in the second box and letting my girls know they have plenty of room now?

    Should I just wait a while longer and let them have a go at working it out for themselves…

    How do you get anything done when people like me keep asking for advice ???


    • John,

      I’m not surprised that they are not building quickly. Remember, backfilling is a way of contracting the size of the nest. Once they start doing that, comb-building will slow down. Instead of ever-increasing the size of their home, they begin to make it smaller.

      Pyramiding, opening the brood nest, and checkerboarding are all methods of countering this impulse. As I said earlier, once a beekeeper notices backfilling, he has to actively manage the colony to prevent swarming. Based on your nectar flows and temperature ranges, you can pick one of these strategies and go for it. I doubt they will work it out themselves–they have swarming on their minds.

      If it’s not too cold and if you have plenty of bees, pull out frames 5 and 7 from the bottom box and replace with empties. Then take those two frames and put them in positions 5 and 6 in the top box. Check on them in a week. But remember, you need lots of bees to do this, or warm nights. Every time you open the nest you run the risk of chilling the brood, so be careful.

  • Hi Rusty,

    This is way off the topic of this post but I can’t seem to find a relevant one. I just opened up my brood nest and about 75% of my frames were stripped to the foundation. Is that something that bees will do?!? The frames that did have comb on them were back filled 😛 There hasn’t been any sign of a queen in this hive for about three weeks either. There is no laying workers so I am not panicking… today. I made a split with this hive because it was over-crowded, so some frames should have new comb on them, but these babies are bare along with 3 or 4 others that should have comb that’s a year and a half old. AM I GOING CRAZY?!?!

    • Chrissy,

      That is strange. I’ve seen comb ripped down by robbers, and I’ve seen animals scrape comb in pursuit of honey, but that doesn’t sound like the case here. Sometimes bees move wax from one place to another, but it sounds like yours is totally missing? I honestly don’t know.

  • Great, I am going crazy. They could be moving wax from the bottom box to the deep above it I suppose. That one is full. What was once was a brood chamber, is no more in either box though. There was one frame with dark comb on it but it wasn’t filled out to the very edges, and I don’t honestly remember seeing a frame this way before. It was like they were taking it starting from the outside moving in. I am so confused!

    When I made my split I took two frames (possibly three but no more) and two more from the deep above it. They have made no motion to build comb on the new frames in the bottom deep and filled the deep above it with honey, not to mention the “case of the missing brood comb”.

    Also, they have filled one honey super… so me being the true genius I am, made an uneducated decision to switch supers. I put the full one on top of the hive and an empty one in the middle, I was afraid they would swarm and thought they would appreciate the extra space. They are not touching the new frames what so ever. It could be that they have inherited my innate ability to just do things all kiddywampus. I’ll wait a couple weeks and check again. Hopefully my brood comb is actually there and maybe today I had “funny” grass in my smoker. Thanks for your help.

  • I have ten hives, seven are going strong , but two hives have filled the second brood box I placed on with solid honey, no pollen or brood. The first brood box has no signs of capped brood. Did I loose the queens in these two hives? I looked as best I could but could not find the queen. Any help you can give would be appreciated.

    • Alan,

      Queens sometimes slow their production in the heat of the summer, but it doesn’t normally stop completely. Do the colonies show queenless behavior, such as short tempers or aggressive flight around the hive?

      If I were in your situation, I would give each of the two hives a frame of eggs and young brood taken from your other hives. That way, if they are queenless they can raise a new queen, and if they are not queenless, no harm is done. Just be sure the frames you transfer do not contain a queen.

      • Thanks for the quick response, saves me the trouble of buying new queens when I really don’t need them.

        Hope to repay the favor sometime in the future.


  • I harvested my first batch of honey. I have NO regular (normal) brood pattern. Instead what I have is vertical cells of brood running UP the comb with honey all around it. I have never seen something like this. On almost all my 3 brood boxes, each frame, it was the same. Columns of brood. I don’t understand. Hive is healthy. I am thinking of re-queening.

  • I love in Utah and our August weather was cooler with a lot more rain than usual. We opened up our hive and found brood in the bottom box, the one above and half of the third box. We have the top two with honey and some pollen. Our colony is huge and honey is limited, why is the queen still laying at this rate? How will they fit in one box to winter over? Our winters are often bitter cold so we’re probably not going to remove any honey this year, will 14 frames get them through? We’re new and confused.

    • Julie,

      If you have 14 completely full deep frames, that is probably enough. That would be roughly 14 X 8 or 112 pounds, which would be enough if the bees don’t move away from it. Sometimes you have to move the honey so it is just above and to either side of the cluster so they can find it.

      I don’t understand if you have three boxes or five. You say you have brood in three and honey and pollen in two, but is there brood in the two with honey and pollen, or are they in addition to the ones with honey and pollen? Sorry, I just don’t have a clear picture.

      With a hive that robust, I would probably overwinter in at least two brood boxes. Either two deeps or a deep and a medium. You are right to think they may not fit into one.

      You can slow the queen down by putting a queen excluder on so she is forced to stay in the lower boxes, and you can also feed heavy syrup so the bees backfill the brood nest and thereby shrink it. Read this post on fall management, if you haven’t already.

  • So I have an issue with wax worms getting into my boxes. I “rent” my bees out to the cucumber farmers for pollination and out of 100 brood chambers probably about 25% have wax worms. Is there any deterrence to keep them out of my hives!?!

    • Savanah,

      There isn’t much you can do except maintain strong colonies. Wax moths usually get started when a colony is too weak to control them, or when the hive is too big for the colony it contains.

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