Cross comb is honeycomb that honey bees build between two adjacent beehive frames instead of keeping it within a single frame. It develops when bees extend comb sideways until it reaches and attaches to the neighboring frame, causing the comb on both frames to become joined. As one of the most common forms of misplaced comb, cross comb can interfere with normal hive management if it is allowed to develop.
Honey bees construct honeycomb primarily for raising brood and storing honey, making it one of the colony’s most valuable resources. Because producing wax requires significant energy, bees build comb only when it is needed. Healthy, well-organized comb is essential for a thriving colony, which is why beekeepers pay close attention to its condition through regular hive inspections and proper management practices.
Cross comb creates significant challenges during hive inspections because connected frames cannot be removed individually without breaking the comb. If it spreads across several frames or covers large areas, it also reduces the usable space within the hive and disrupts the orderly arrangement of brood and food stores. As a result, beekeepers work to prevent cross comb from forming and remove it promptly whenever it is discovered.
Using foundation in beehive frames is one of the most effective ways to prevent cross comb. Foundation provides bees with a clear guide for drawing straight, properly aligned comb, greatly reducing the likelihood of sideways growth. Although this article discusses the role of foundation in greater detail later, it is worth noting here that many beekeepers choose foundationless systems for natural or organic beekeeping. Whether to use foundation ultimately depends on the beekeeper’s management goals and personal preferences.
For beginner beekeepers, using foundation in alternating frames can help guide comb construction and minimize the risk of cross comb. Both plastic and wax foundation are suitable options. Some beekeepers avoid foundation because of concerns about introducing chemical residues into the hive, but this risk can be minimized by purchasing high-quality, contaminant-free foundation from reputable suppliers.
In the wild, honey bee colonies naturally replace old comb over time, ensuring that fresh comb is continually introduced into the nest. This natural renewal process is not always replicated in managed hives, allowing old comb to accumulate, increasing the risk of disease, and reducing colony productivity. Queen bees also prefer laying eggs in newly drawn comb rather than old, dark comb. To maintain healthy colonies, brood comb should generally be replaced on a three-year rotation where disease pressure is low. In areas where brood diseases are common or pose a significant threat, comb should be replaced more frequently with freshly drawn comb.
How Cross Comb Is Formed
Honey bees build comb primarily for brood rearing and honey storage, although it also plays important roles in regulating hive temperature and transmitting vibrations used for communication within the colony. Comb is naturally constructed in a nearly vertical plane because bees rely on gravity to guide its alignment. This behavior is seen in both wild colonies and managed hives. Bees only produce new comb when it is needed, which is why comb construction is most active during the warmer months, particularly from late spring through summer.
Honeycomb is not always perfectly flat. It can bulge outward, and the depth of individual cells may vary depending on their purpose. Queen cells project prominently from the comb, while drone cells are slightly larger than worker cells. Under natural conditions, combs are typically spaced 30–32 mm apart, with cells averaging 11–12 mm in depth. When comb becomes excessively thick or bulges into the bee space between adjacent frames, bees may connect the two combs. These attachments eventually develop into cross comb.
Incorrect frame spacing is one of the most common causes of cross comb. Frames that are positioned too close together or too far apart disrupt the proper bee space between them, encouraging bees to build comb that extends into neighboring frames. During hive inspections, even a small mistake in replacing frames can alter their spacing and lead to cross comb formation.
Reasons Why Bees Build Cross Comb
Like other forms of misplaced comb, cross comb usually develops because of a leaning hive, incorrect frame spacing, or the bees’ attempt to strengthen comb they perceive as weak. These conditions can occur in any hive design, including Langstroth, Warre, and top-bar hives, making cross comb a problem that affects all styles of beekeeping.
1. An Uneven Beehive
A hive that is not level can cause bees to misinterpret the direction of gravity, resulting in comb that is built at an angle rather than vertically. As the comb extends downward from the top bar, it may eventually come into contact with comb on the adjacent frame, especially in the direction of the lean. In most cases, the two combs meet near the bottom of the frames because honey bees naturally build comb from the top downward.
If the hive is severely tilted, the comb may intersect with neighboring comb much higher on the frame. A hive that was originally level can become uneven over time if its stand weakens or sinks into the ground. This commonly occurs during heavy nectar flows, when the increased weight of honey causes the hive stand or supporting surface to settle unevenly.
2. Perceived Weakness of Comb
Honey bees sometimes build cross comb because they believe existing comb requires additional support. What begins as brace comb intended to strengthen a weak section can eventually connect to adjacent comb, forming cross comb. Freshly drawn comb is relatively soft and flexible, especially before it has been reinforced with brood or stored honey. High temperatures can make it even more fragile.
This problem is most common in foundationless systems, where newly constructed comb hangs freely from the top bar until it is fully developed. Bees may strengthen these unsupported sections by adding connecting comb. Although cross comb can occur in any hive type, Langstroth hives generally provide the greatest support because their frames support comb along the sides during construction and at the bottom once it is fully drawn.
3. Improperly Spaced Frames
Maintaining correct bee space between frames is essential for orderly comb construction. In Langstroth hives, the frames act as guides that encourage bees to build straight comb. When frames are placed too close together, the comb on one frame can extend into the space intended for the neighboring frame, increasing the likelihood of cross comb.
Frames that are spaced too far apart can also create problems. Bees may build thicker comb or extend the cell walls outward to achieve the proper cell depth of 11–12 mm. As these projections grow, they can eventually touch the comb on adjacent frames and become connected.
4. Failure to Remove Old Queen Cells
Queen cells are much larger than worker and drone cells and project noticeably from the surface of the comb. They are built whenever the colony is raising new queens, whether for swarming or queen replacement. After a queen emerges, worker bees often leave the empty queen cell in place rather than removing it.
These protruding queen cells can eventually come into contact with comb on neighboring frames. Bees may then build additional wax around the area, gradually creating thick masses of connected comb that develop into cross comb.
5. Repurposing Honeycomb
Honey bees frequently change the purpose of existing comb as the colony’s needs evolve. Brood comb is generally thinner than comb used for storing honey because brood cells do not require the extended walls needed to hold large amounts of nectar and capped honey. Consequently, brood comb is separated by approximately two bee spaces, while honey storage comb requires only a single bee space between adjacent combs.
When brood comb is converted into honey storage comb, bees deepen the cells by extending them outward. If previously drawn comb is already installed in the hive, this expansion can significantly reduce the space between neighboring frames. As the comb thickens, it may eventually touch adjacent comb, leading to the formation of cross comb.
Issues Caused by Cross Comb
Although honey bees generally function well with cross comb, it creates numerous challenges for beekeepers. Routine hive inspections become more difficult because connected frames cannot be removed individually. If a beekeeper is unaware that two frames are joined by cross comb, lifting one frame can tear away comb from the other, causing unnecessary damage. Since hive inspections require frames to be removed one at a time, cross comb significantly increases the risk of breaking comb that contains brood, honey, or pollen.
Cross comb can also cause problems during honey harvesting and the collection of other hive products. As frames are removed, connected comb may tear away from one or both frames, resulting in the loss of brood, pollen, or stored honey. Before removing a frame, it is good practice to gently move it from side to side to determine whether it is attached to the neighboring frame. If two frames are connected by cross comb, removing them together is often the safest approach and helps preserve the integrity of the comb.
Warre and top-bar hives experience similar difficulties, even though they do not use conventional frames. Instead, these hives rely on removable top bars, which are lifted individually during inspections and harvesting. When comb built from neighboring bars becomes connected, lifting one bar before the other can tear the comb, creating the same management challenges found in Langstroth hives.
Minor comb damage during honey harvesting may be acceptable for small-scale beekeeping because honey extraction often involves uncapping or cutting comb. If only a small amount of comb is damaged by cross comb, the overall loss of honey is usually minimal. However, the situation becomes much more serious when cross comb damages brood comb or newly constructed comb during periods when the colony depends heavily on it for brood rearing or food storage.
Important Considerations
During spring and summer, honey bee colonies expand rapidly by raising large amounts of brood and storing nectar and honey. These are also the seasons when bees construct the greatest amount of new comb because colony demand is at its highest.
Extensive damage caused by cross comb during these critical periods can limit colony growth and reduce the amount of honey that the bees are able to store. As a result, the colony may be less productive, and the beekeeper may harvest a smaller honey crop at the end of the season.
Because comb is so valuable to the colony, beekeepers aim to prevent cross comb from developing and remove or correct it as soon as it is discovered.
Preventing Cross Comb
Preventing cross comb should be one of the primary goals of every beekeeper. Although it is difficult to avoid completely throughout a beekeeping career, good hive management can greatly reduce its occurrence. Successful prevention depends on eliminating or minimizing the conditions that encourage bees to build cross comb, including uneven hives, improper frame spacing, unsupported comb, and neglected hive maintenance.
When cross comb is detected at an early stage, it can often be corrected before it becomes a major problem. A small cut at the point where the comb is attached may allow it to be gently repositioned into the proper alignment. After straightening the comb, it should be securely reattached to the top bar or frame using an appropriate hive tool or another suitable method to ensure it remains stable.
1. Using Foundation
Providing bees with foundation is one of the most effective ways to encourage straight comb construction and reduce the likelihood of cross comb. Foundation serves as a guide that directs bees to build comb in the correct plane. Its use is generally limited to Langstroth hives because Warre and top-bar hives are designed primarily for foundationless beekeeping. Consequently, cross comb tends to occur more frequently in foundationless hive systems. Beekeepers who prefer a more natural approach can reduce the risk by alternating frames fitted with foundation and foundationless frames.
2. Keep Hives Level
Maintaining a perfectly level hive is another essential step in preventing cross comb. A spirit level should be used whenever a hive is installed or relocated, and the hive should be checked periodically throughout the year. Seasonal changes in hive weight, especially during heavy nectar flows, can cause hive stands to settle unevenly and create a slight tilt that encourages crooked comb construction.
Hive stability is equally important. Beehives should always rest on strong, stable stands capable of supporting their full weight. Inspect hive stands regularly for loose joints, rotting wood, corrosion, or sinking legs, and repair or replace damaged components as needed. Suspended top-bar hives are particularly susceptible to movement in windy locations. Installing a windbreak or reducing excessive swinging helps prevent bees from responding to constant motion by building cross comb.
3. Remove Old Queen Cells
Empty queen cells should be removed soon after new queens emerge. Because queen cells protrude well beyond the surface of normal comb, they can come into contact with neighboring comb and encourage bees to build connecting wax around them. Removing old queen cells is especially important when they face adjacent frames or comb surfaces.
4. Use Properly Sized Equipment
Using accurately manufactured hive equipment helps maintain the correct bee space throughout the hive. Hive boxes, frames, top bars, and other components should conform to standard dimensions. Spaces that are smaller than the natural bee space are typically sealed with propolis, while spaces that are too large encourage bees to build excess comb. In top-bar hives and other cavity-style hives, incorrect spacing between bars can easily result in comb that is misaligned or connected by cross comb.
5. Inspect Hives Regularly
Regular hive inspections are the most effective way to detect cross comb before it becomes a serious problem. Early detection allows the beekeeper to straighten or remove misplaced comb while it is still small and manageable. During every inspection, check not only for developing cross comb but also for the conditions that encourage its formation, such as uneven hive placement, improper frame spacing, old queen cells, and weak or unsupported comb. Consistent monitoring and timely corrective action greatly reduce the likelihood of extensive cross comb developing in the hive.
How to Remove Cross Comb
When cross comb becomes extensive, removing it is usually the only practical solution. A hive tool is the best tool for this task, as it allows you to carefully cut through the connecting comb and separate the attached frames. During the process, some cells containing brood, honey, or pollen may be damaged, but this is often unavoidable. If the cross comb covers a large area, sections of honeycomb may need to be cut away completely to restore proper frame separation and allow normal hive management.
The pieces of comb removed during the process should be saved whenever possible. They can be rendered into beeswax for future use or returned to the hive, where the bees may recycle the wax when constructing new comb. If the removed comb must be discarded, place it well away from the apiary to avoid attracting ants, wasps, rodents, or other predators and pests that could threaten the colony.
Careful preparation makes cross comb removal safer and more efficient. Wear appropriate protective clothing before opening the hive, and keep a smoker nearby in case the colony becomes defensive during the operation. It is also helpful to bring a suitable container for collecting the removed comb, keeping the work area organized and preventing wax and honey from being scattered around the apiary.
After removing the cross comb, take time to identify and correct the conditions that caused it to develop. Check that the hive is level, ensure the stand is stable, verify that frames or top bars are correctly spaced, and remove any old queen cell remnants that could encourage additional comb growth. Addressing these underlying issues greatly reduces the likelihood of cross comb forming again and makes future hive inspections much easier.
Conclusion
Honey bees build comb to rear brood, store honey and pollen, regulate the hive environment, and support the daily activities of the colony. In Langstroth hives, comb is constructed within removable frames, while in Warre and top-bar hives it hangs from top bars. Ideally, comb should be drawn in straight, vertical sheets that maintain the proper bee space throughout the hive. Most cases of cross comb result from manageable factors such as uneven hives, incorrect frame spacing, unsupported comb, or inadequate hive maintenance. By understanding these causes and applying sound beekeeping practices, beekeepers can prevent most cross comb, simplify hive management, and maintain healthy, productive colonies.