by David Blocher

One of the greatest challenges in beekeeping, especially with an overwintered hive, is keeping your bees (i.e., preventing your bees from swarming).  Swarming is a biological imperative, and almost all colonies will attempt to swarm.  Swarming, though, is a bane to the beekeeper, can be a nuisance to your neighbors, and if your goal is honey production, the potential for a substantial crop disappears with the swarm.

A second challenge is preventing your colony from swarming without expanding your number of colonies. There are a number of swarm prevention techniques but most result in an increase in colony numbers after the manipulation. This requires buying an additional bottom board, inner cover, and outer cover or additional deep hive bodies and frames and foundation.  If you are not careful, you can have exponential colony growth and quickly become a commercial beekeeper.  Finally, avoiding swarming by increasing your colonies doesn’t maximize honey production—if anything, after splitting your colony into two units, your surplus honey production will likely be minimal.

Since dealing with swarming is a problem everyone faces with an overwintered hive, I thought I’d share a technique that has worked for me over the years.  I’m not the inventor of it by any means—Richard Taylor described it years ago in a Bee Culture article, and the elegance and simplicity of it bespeaks a deep knowledge of honey bee biology (which he probably learned about from somebody else…).  By the way, this is the only swarm prevention technique that is curiously not discussed in his excellent treatise on producing comb honey, “The Comb Honey Book.”

This technique has the following advantages:

  • It is a guaranteed way to keep your bees if you find uncapped queen cells in your hive, which is a sure sign that the hive will be swarming shortly.
  • You do not need to buy an additional bottom board, inner cover or outer cover. 
  • After the manipulation is complete, you have the same number of colonies as when you started
  • You’ve kept the full strength of your hive for the nectar flow
  • It allows you to retain the genetics of the existing queen if you want to raise daughter queens from her.  Perhaps her offspring show some mite resistance or are exceptional honey producers.


I generally try to super my colonies by about the first week in May, and begin checking strong hives around the same time for signs of the swarming impulse (developing queen cells, exploding populations and crowded conditions).  By May 15th, the colonies are often bringing in surplus honey. My rule of thumb at this time, is that if a colony isn’t making honey, they’re making queen cells and preparing to swarm.  That is, if the colony has enough bees to be in the supers, and good flight weather prevails–yet they are not gathering honey–you can be sure they are preparing to swarm. You should begin looking for queen cells in earnest.


The technique is based on the following three simple principles of bee biology:

  1. Bees cannot swarm without a queen.
  2. Bees cannot raise a queen if they do not have the necessary eggs or larvae.
  3. A queenright hive will not swarm if there is no population pressure.

Make sure you understand these principles.  Re-read these if necessary.  I’ll wait.


Also, this manipulation assumes that your colony is in two deep hive bodies, but it could work just as well with three medium supers, if that is your configuration.  It does require three important things

  1. You must purchase or make a double screen board (see picture below), also called a Snelgrove board after its inventor. (An inner cover with duct tape over the oval on both sides will work in a pinch, but only if the inner cover has a ventilation notch cut in it.)
  2. You must locate the queen.
  3. As with all swarm prevention techniques, you must remove developing queen cells, unless you intend to raise a queen to replace the existing queen.  In that case, leave 1 or 2 queen cells in the queenless portion of the hive, but remove the rest.

     Double screen board with entrance gate open (this entrance will be at the back of the hive)

Let’s say you crack open your hive and find swarm (aka queen) cells hanging from the bottom of the frames in the top deep.  It’s time to go to work.  We want to perform the following three steps upon seeing the first queen cells with eggs or larvae in them. 

  1. Put all the CAPPED BROOD in one hive body, making sure the queen IS NOT on these frames.  Try to avoid putting frames with eggs or open brood in this deep hive body, but if you have some open brood—which often cannot be avoided—that’s OK.  This hive body with capped brood will remain on the bottom board.  This portion of the colony is now queenless.  
  2. Put the honey supers back on top of this hive body, and place the double screen board on top of them with the entrance at the back.
  3. Put all of the OPEN BROOD and the QUEEN into the other hive body, along with some frames of pollen and honey.  Place this on the double screen board, and put the inner and outer covers on this hive.

We will leave the hive in this configuration for 10-14 days, and then reunite at the end of this period.


Why does this technique work?

  1. Review the first two biological principles above.  By placing all of the capped brood in the bottom hive body and making this half of the hive queenless, you have prevented the bees from raising an emergency queen.  These bees will not leave the capped brood, and they cannot leave the hive in a swarm since they do not have a queen.
  2. Review the third principle of bee biology. In the queenright portion of the hive you have reduced the population pressure, by placing its entrance at the back of the hive.  All of the foragers will return to the main entrance at the front of the hive. The top half of the hive—the queenright portion, has been effectively depopulated, and only the nurse bees remain with their queen to tend to the developing brood.  
  3. You have simulated a swarm while at the same time managing it.  After 10-14 days the swarm urge has passed.  You don’t want to leave them separated for any longer than about 14 days, because at that point, all of the capped brood down below has emerged, and they would otherwise begin to fill these empty cells with nectar.  Instead, at this point, you want the queen to start using these empty cells to lay more eggs in.  In the meantime, they have been filling your honey supers with lots of nectar!


Two big caveats:  because they are queenless, they will be desperate to have a queen.  If you have had to put ANY frames of eggs or larvae in the bottom hive body with the capped brood you must go back one week later and destroy the developing queen cells that they have begun to raise.  Otherwise, you will soon have a queen in that deep hive body!  Second, as with any swarm prevention technique, you must remove all of the queen cells, unless you leave one or two in the queenless portion in order to requeen that part of the hive.

Reuniting the two portions of the hive

After 14 days (2 weekends for the backyard beekeeper), you will want to recombine the two hive bodies.  The reason for this timing is that the capped brood in the nest in the bottom deep will all have emerged by now, and the colony will be filling these cells up with nectar.  Of course, they will also have been filling up your honey supers with nectar since all of the cells in the deep hive body were filled with brood, so don’t be surprised if the honey supers are quite heavy already—they have had no brood to feed, so their attention has been devoted to nectar collection.  Also, at this point, the urge to swarm has passed.

Two weeks after the manipulation, reunite the colony using a newspaper between the two hive bodies.  This is probably not strictly necessary, but I always do it.  The bottom deep is filled with young bees that have emerged, and they are desperate for a queen.  I always place the queenright portion as the second deep hive body, and then put the honey supers above it (using a queen excluder).  Any nectar that they have put in the bottom deep hive body will soon be moved into the honey supers, since bees don’t store honey below the nest as a general rule, only above it.  

This is a great technique—especially if the hive is in the middle of swarm preparations—because you keep the full strength of your colony for the main nectar flow, you get to preserve the hive’s genetics, and it does not result in an increase in the number of colonies.  However, as with any time-sensitive hive manipulation, you must check for emergency queen cells a week after splitting the colony, and then reunite them after two weeks.  It is also quite flexible. It also lends itself to requeening the hive quite easily, either by allowing a queen cell to emerge in the queenless portion, or by adding a purchased queen.  In either case, leave the mother queen in the colony above until you combine the two, and then dispatch her.  Let your imagination run wild—and good luck!