Burr Comb: What Is It? And Why is it a Problem?

Honeybees build comb for lots of different reasons. As beekeepers, it works out best when the comb is confined to the frames and foundations we provide. Bees, on the other hand, often have ideas of their own and choose to build comb in undesirable places ... undesirable for beekeepers, that is. An excess, ill-placed comb is called “burr comb,” and it can make hive inspections quite difficult if left unchecked. Fortunately, there are things you can do to reduce excess comb in your hives.

“Bee Space” in the Hive

Bees are very efficient in their use of space. They’re constantly in the process of building new comb when it’s needed wherever space allows. Most modern hives are built to the specifications set up by Reverend Lorenzo Langstroth, the father of American beekeeping and the creator of the Langstroth hive. Reverend Langstroth and other early beekeepers found that bees set aside a certain amount of space when they built comb.

The spacing between each sheet of comb measures approximately 3/8” — the amount of space required for bees to maneuver between the sheets of comb. Often referred to as “bee space,” this measurement is used in the design of modern hives.

Hive components, however, may not always be built to exact specifications, plus the box and frame sizes can vary from one manufacturer to the next. When this happens, the bees find themselves with more space than they need, and they fill it with “excess” comb.

Common Locations of Burr Comb

The most common location for burr comb is on top of the wooden frames. The spacing between brood boxes and supers is greater than 3/8”, and, as we’ve already stated, the bees will try to fully utilize the space. Burr comb often makes it difficult to remove frames from the hive because it can cement the frames together. That’s just one reason why it’s best to remove any burr comb you come across when performing a hive inspection.

The second place you’ll frequently find burr comb is on the interior walls of the hive.

Burr comb is easily removed by scraping it from hive components using a hive tool.

Excess Wax and Pests

Burr comb is a great hiding place for pests such as hive beetles and wax moths. This is another important reason to keep excess comb under control in your hives.

Mistakes Lead to the Creation of Burr Comb

Mistakes made by beekeepers often lead to the creation of burr comb. This includes forgetting to put all frames back into the box or failing to push the frames together after an inspection. Both scenarios can lead to the creation of excess comb to fill any space larger than the required “bee space”.

If this occurs, it’s important to remove the excess comb before it becomes an even greater problem. The longer excess comb remains, the bigger a problem it will become. The bees continue to add more and more wax, making frames difficult to remove and boxes/supers hard to separate.

Once bees determine the spacing is off, they will continue to fill it. This will require diligence on your part to remove it each time a hive inspection is performed.

Extra Wax Endangers the Queen

When the worker bees create burr comb, the queen may decide to lay eggs in it. If the burr comb is large enough, the queen could be working inside it, and you be unaware of her presence. If she is inside the comb when you remove it or remove frames that result in a tear to the comb, the queen could be hurt or killed. This is just one more reason to stay on top of the excess comb in your hives, removing it while small.

Burr Comb and Drone Brood

Burr comb often contains bee larvae or brood. It can be difficult for beekeepers to destroy brood when removing the excess comb, but it’s a necessary evil.

Many times, the brood found in burr comb will be drones because drone brood is often located on the outer edges of the brood nest. (Check out this blog post for more information concerning drone brood and hive inspections.)

If drone brood is present in the burr comb, use this opportunity to look inside and examine the brood cells. Varroa mites prefer drone brood; therefore, closely examine the larva in the burr comb you have removed, especially drone cells. Does the larva have reddish spots? If you find evidence of mites (reddish spots), perform a varroa mite test immediately. If mites are present, don’t delay treatment.

Discard Burr Comb?

What should you do with the extra comb you remove from your hives? You can use it for a beeswax project, such as making soaps, lotions, balms or candles. Place small pieces in a container until you have enough for a project.

What not to do with the burr comb? Do not discard it on the ground in the vicinity of your hives. Its scent will attract pests (bears, skunks and raccoons), as well as robbers (wasps and other bees) to your apiary.

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That wraps up our discussion of burr comb. Join us next time as we continue to look at other types of excess comb, such as brace comb, cross comb and bridge comb.