Bridge Comb: What is it? And Why is it a Problem?

Honeybees build comb for several reasons — to raise their young, to create honey and to store food supplies for winter consumption. Ideally, they’ll form comb within the frames that their beekeeper provides, but sometimes this just isn’t the case. In our last blog post, we discussed burr comb and found that it was built when the bees found extra “space” in the hive. Being efficient, they want to fill all space available to them because it’s easier for them to maintain.

Usually, comb is built vertically and extends to a uniform thickness, allowing for a “bee space” width between combs. “Bee space” is approximately 3/8” — the space required for bees to move around between the sheets of comb.

Sometimes, however, bees will build comb sideways, joining two or more frames. This is referred to as bridge comb and is another type of burr comb. It’s a nuisance and causes considerable damage to comb, brood and honey stores when frames are removed from the hive.

Bridge Comb Equals Loss

Bridge comb is problematic for many reasons, and all of them equals loss. Building comb requires a lot of effort on the part of bees. When the comb is torn upon the removal of frames, that effort is wasted. Bridge comb that connects two or more frames always results in loss when a connected frame is removed. This loss may include:

• Empty comb
• Comb containing honey or pollen
• Comb containing eggs or brood
• Loss of bees who are trapped or crushed

Therefore, beekeepers should be diligent in its removal and do what they can to prevent its formation in the future.

Why do Bees Build Bridge Comb?

Understanding why bees build bridge comb is the first step towards its prevention. It’s a common problem and even the most experienced beekeeper may encounter bridge comb at least once or twice a year.

Bees build bridge comb for the following reasons:

• The hive is not level — because gravity impacts comb development, a hive that is not level is more likely to have bridge comb.
• Improperly built hive components — when hive components allow spacing to be more than the bees require — bee space — bridge comb is more likely to appear. Therefore, it’s best to purchase all hive components from the same manufacturer. Components from different manufacturers may not fit together correctly.
• Bee space is not right — when the frames are not properly inserted into the hive body or when a frame is omitted, bridge comb may result.

The Challenges of Bridge Comb

Bridge comb is not a problem to the bees, to them, it’s just comb. To the beekeeper, however, bridge comb is a problem for the following reasons:

• Makes hive inspections difficult — comb is torn when it’s attached to multiple frames or the interior of the hive body.
• Bees can be injured or killed when the comb breaks away and/or falls.
• Breaking and falling comb can cause bees to become aggressive.
• Bridge comb causes a reduction in honey production due to wasted effort on the part of the bees.
• Brood in the bridge comb that is removed dies.

Prevention of Bridge Comb

Take the following measures to reduce the creation of comb in unwanted spaces:

• Ensure that the hive is level
• Provide frames with foundation, clearly defining where the comb should be built
• Perform frequent hive inspections to keep unwanted comb in check
• Ensure all components fit together properly, eliminating gaps and spaces beyond “bee space” whenever possible

If caught in the early stages, any wayward formed comb can sometimes be nudged back into alignment within a frame.

Bridge Comb Removal

Bridge comb should be removed as soon as it’s discovered using a hive tool or a sharp knife.

Brush all visible bees from the comb before removing it from the hive. Inspect the comb upon removal, ensuring that the queen is not in the comb.

Do not discard bridge comb in the apiary. The scent can draw predators and/or robbers to your apiary.

Choosing to Leave Bridge Comb

When bridge comb is found in the brood box, a beekeeper may choose to allow it to remain. If the comb contains a lot of brood and the bees are working it, you may decide to leave it as is to increase the number of bees in your hive, especially in the spring when you want the number of bees to increase rapidly. You can decide to remove the comb later when the weather begins to cool again in the fall and winter.

General Questions About Bridge Comb

How Often Should Beekeepers Inspect Hives to Prevent Bridge Comb Formation Effectively?

Inspect hives every two to three weeks during the active season, from spring to fall. Regular inspections help catch and correct issues like bridge comb early before they become disruptive.

What Steps Ensure Proper Fitting of Hive Components?

Ensure standardization and alignment of hive components, especially when using parts from different manufacturers. Use a carpenter's level during assembly to align frames and boxes, minimizing gaps. Regularly check frame spacing and adjust as needed during inspections to prevent bridge comb formation.

Are Certain Bee Breeds More Prone to Building Bridge Combs?

There's no consensus on bee breed influence regarding bridge comb formation. Environmental conditions and hive management play larger roles. Bees in suboptimal conditions or poorly constructed hives may develop bridge comb more often.

How Can Beekeepers Repurpose Removed Bridge Comb Instead of Discarding It?

Bridge comb containing honey can be extracted, while comb with pollen or partially built comb can be melted for valuable wax. Clean, intact comb can sometimes be reintroduced to the hive for repair, conserving resources and benefiting the colony.

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In closing ... it’s best to stay on top of bridge comb, removing it as soon as it’s discovered. This requires timely and frequent hive inspections.