Hive Box Insulation for Bees & Beekeepers

When to Intervene and When to Let Them Bee

Wood hives, polyurethane boxes, or an entire tree trunk? Multiple materials exist for use as a hive body, and it’s up to the beekeeper to decide the long term approach. Wood is lindy and durable. Polyurethane and plastics have better insulation properties but require more frequent maintenance. A hollowed-out tree trunk is perhaps the natural-est option of them all, yet it’s the hardest to manage & manipulate.

What makes a good bee box? Consider the geography, cost, and maintenance requirements before going all in. If you’re looking to get started without fuss, opt for the wooden box; it’s good enough to teach you the basics of beekeeping and will last years. If you’re in harsher climates or want to optimise your colonies, then the plastic options are for you.

This article expands upon the post on hive temperature control, and its theory-heavy cousin “how bees manage temperature extremes“. Several hive types available on the market, each with their own merits. You’ll find that plastic-based hives improve productivity and overwintering success and avoid the issue of wood-boring pests, at the expense of environmental harm own the line.

Insulative Properties of Hive Boxes

Insulation protects from temperature extremes. Bees maintain a brood nest around 35°C and 50% relative humidity for proper larval development. The hive box materials and its thickness determine how much energy the bees expend on cooling or heating. The average wooden hive thickness is 23 mm – an inch of wood is not much, and its insulative properties have been surpassed by new materials (Alburaki & Corona 2021).

In winter clusters, bees dedicate significant resources to maintain that optimal 35°C. The aforementioned study by Alburaki & Corana suggest that a polyurethane hive is the superior choice in locations with cold winters. These polyurethane Langstroth hives maintained a higher inner temperature and lower humidity than the wooden hives, with smaller fluctuations.

When outside temperatures were close to 0°C, the average hive box temperature was 10.2 °C and 9.73 °C for polyurethane and wood respectively – significant enough to help a weak colony survive. Perhaps the variations in wooden box humidity are explained by the material’s ability to absorb water vapours and release it at higher temperatures (i.e. daytime)? The bottom line: if bees spent less time on temperature management, then more time is dedicated to brood rearing, honey production or survival.

Polystyrene & Composite Hives Produce More Honey

Erdogan compared the springtime honey production of wooden, polystyrene & composite Langstroth hives (“composite” being mixture of poly-something materials; Erdogan 2019). He found that colonies in composite boxes produced 35% more honey, and those in polystyrene hives 21% more than wooden hive boxes.

Colonies in insulated hives had more developing brood, which led to more adult worker bees and therefore more foragers and hive members in general. There was an initial drop in nectar levels when more young adults were present- understandable, for they are not foragers and so consumed the gathered nectar. Once the bees matured, the hive stores increased owing to the abundance of foraging bees. These bees were more productive and started foraging earlier in the day, as the increased insulation led to higher overnight temperatures. The early bee gets the blossom, and these hives outcompeted their less-insulated neighbours.

Bees Kept in Plastic Hives are More Aggressive

Bees kept in insulated hives were more aggressive during inspections. Sure, defensive behaviours are influenced by genetics and other factors, but Erdogan argues that humidity, air circulation, and temperature are “[some] of the most important factors that provoked the honey bees” (Erdogan 2019). He suggests that higher hive humidity to be the cause, as wooden hives could absorb and release the moisture naturally.

A questionable result, for statistical significance and real-world significance are not the same ting… It’s something to keep in mind when approaching insulated hives.

Multi-box Dimensions: Ideal, Deep or Full Depth?

Langstroth box dimensions differ in response to the needs of bees and wants of beekeepers. Bees want a nesting cavity volume around 42 L, which is achieved by an average 8-frame, full-depth hive body. For more honey production, add additional full-depth supers, but not too many, or the excess space will stress the colony. If you’d prefer the bees to make their honey faster and in smaller batches, the “ideal” box has a volume around 10L¹.  The bonus upside is not having to carry a 40-something kilogram super from the apiary to the extraction shed.

The smaller-sized boxes are better suited to cold climates, as they minimise the amount of volume added onto the colony. This would be the recommended approach for many beekeepers, but the need for additional costs and storage space (ideal-sized boxes and frames) may deter you.

I currently use full-depth 10-frame wooden boxes for all my hives. My suburban area has mild winters and year-round forage, giving me flexibility in apiary setup. I used to have three boxes per colony– two supers and one brood box. Now, I’m opting for one super and one brood box as I believe it less stressful for the bees- less room to maintain and patrol, and easier for me to inspect and manage.

How to Choose the Right Box

Further comments:

• If you’re new and want to get started right away, consider buying:
  • Two eight frame full-depth boxes,
  • 16 foundation frames,
  • hive base (screened base preferred) & migratory lid,
  • A smoker and a hive tool,
  • Bees, with a laying queen (catch a swarm, buy a package or transfer frames from a nuc).
• In locations with extreme heat or cold, opt for a plastic box. As you read from Erdogan’s work above, composite boxes provide superior insulation from less-than-ideal temperatures (Erdogan 2019). If bees dedicate less energy to temperature regulation, then more time is spent on brood rearing or foraging.
• Full honey supers are heavy (40-50kg). If manual labour is not your thing, opt for an Ideal (“half size”) or WSP (“three-quarters”) box structure. The bees will fill the smaller frames faster, giving you more frequent honey yields at lower volumes. For those backyard beekeepers with time on their hands, increased extraction frequency is not a problem. For commercial beekeepers… a different story.

Log & Top Bar Hives as a Natural Beekeeping Approach

Tree hives have been used for hundreds of years on family estates and woodlands. They are still used today in parts of Europe, Africa and Asia, with tree beekeeping continuing in Eastern Europe.

In a live tree, scout bees inspect the trunk cavity to determine its suitability. A log hive mimics tree hives, designed according to the bee’s nesting preferences. Fashioned from hollowed logs, they are an inexpensive approach to beekeeping; no frames or add-ons required². The design is convenient for beekeeping in remote areas, as the materials for modern hive constructions are not readily available.

A top bar hive uses a horizontal wooden trough with “top bars” to guide comb construction- bees build on the bars and expand their hives horizontally. It is similar to the log hive as it uses no foundations, and whole combs are cut out for extraction, the difference being in construction and addition of top bars to the hive box.

Warre Hives as an Intermediate Between Log and Langstroth Hives

Adapted from “Honeylocked Hives”

I consider Warre hives an intermediate between the “all natural” log hives and commercialised Langstroth hives. No queen excluder is used, and the colony expands downwards by undersupering (as opposed to the regular additions of supers on top of Langstroth hives). This vertical stacking causes bees to build comb downward as they do in nature. The top boxes will hold honey, whilst brood is continually moved towards the bottom where temperature regulation is easier.

The frames of Warre hives are foundationless (or with a small starter strip); the bees construct comb according to their needs, rather than a pre-set size. A quilt is placed on the topmost box, containing insulating materials like woodchips to aid in temperature and moisture regulation- This reduces condensation during the colder months, very much mimicking a tree cavity.

Bottom Board Structures

It used to be solid wooden boards for all Langstroth hives. This wooden base improves cold insulation, leaving the hive entrance as the sole source of ventilation. With the rise of Varroa mites, screened, “meshed” bases because prevalent. Screened boards stopped fallen mites from climbing back on bees, and also improved ventilation via the bottom boards, and were more suitable for beekeeping in warmer climates.

Beneath the mesh was a (typically) plastic bottom board that is used to capture hive debris. This could be further manipulated for insulation (addition of foam or additional openings for cold and hot conditions respectively) or pest management. Regarding the latter, Yours Truly uses vegetable oil or diatomaceous earth to kill any fallen creature – mite, moth or beetle. Others like Jayapal and colleagues suggest a sheet of mica dustings to capture and trap pests, in this case, wax moths (Jayapal et al., 2022).

A layer of mica dusting is attached to the “trough” of the bottom board, and the surrounding spaces sealed off to create an isolated chamber- a space below the mesh, but above the bottom board. Any creature that falls through cannot escape to the surrounding vegetation, and is forced in this enclosure (Mathialagan et al., 2019). In the case of wax moths, Mathialagan and colleagues found that trapped larvae would pupate and remain in this space then die. The disruptions to the wax moth life cycle reduced the burden of infestation on colonies, suggesting that laminated bottom board sheets a non-chemical approach to pupating pest control. As a bonus, Varroa is also impacted (the dust kills them).

Hive Lids are for Transport, Ventilation and Feeding

I recognise two types of Langstroth hive lids:

• Telescopic lids, for weather protection.
  • They have a top cover that extends over the sides of the hive, much like a telescoping tube.
• Migratory lids, for easy stacking and transport.
  • These are flat lids that sit “flush” on the sides of the hive, and are common in Australia

From these two types, hybrids emerge, such as the pigeon lid which I used to use for ventilation. Unfortunately, that lid had a habit of jutting out over the edge of the box, making inspections difficult- the bees would seal it tight with burr comb and propolis… cheeky buggers.

The major accessories to the hive lids are the inner covers, which are placed between the lid and the topmost box. Some designs may have a central hole is made for mounting an in-hive feeder. On its own, the inner lid provides insulation, reduces moisture buildup, and increases ventilation. Like the hive bodies above, the lids can be made from polystyrene and other insulating material, to meet the beekeeper’s needs.

Termites invading Honey Bee hives

The easiest way to avoid a termite problem is to use non-wooden hives.

Termites attack wooden structures, leading to degradation and possible collapse of the hive box. This repetitive structural damage exposes bees to environmental stressors and makes it easier for disease and predators to strike. While bees may be able to seal the visible cracks and damages with propolis, the lack of structural stability means the fate of the box is uncertain under extreme conditions, like strong winds.

As with building a house, the materials used in hive box construction determines the colony’s susceptibility to termite attacks. By using treated wood, beekeepers can reduce the risk of infestations, so long as it suits the local environment and prevalent termite species. In Nigeria, Aiyeloja and colleagues found that termites were more likely to infest hives during the wet seasons as they are more active in higher humidities (Aiyeloja et al., 2014). In colonised hives, termites attacked from the rear and were active at towards the back and on the top bars– these areas cannot be reached by bees, enabling the smaller termite to eat away at the wood.

If a guard bee encounter termites, she defends her colony by fanning her wings and blowing the smaller insect away (Yang et al., 2009). This was true of any smaller insect, be it ant, aphid or termite. However, most termite activity (tunnelling) occurred at night when the bees were less active, and once those tunnels were formed, the daylight movement often goes unnoticed.

Elevating the hive with iron stands was insufficient, as the termites climbed them. To prevent termite infestations, the authors recommend a throughout termite search of an area prior to establishing an apiary (Aiyeloja et al., 2014). Where an apiary is already established, the advice is to move non-infested colonies to dry locations during the wet season. Protecting hives from termites is up to the beekeeper rather than the bees. Good luck.

What Makes a Good Hive Structure?

This was a companion article to the post on hive temperature control. A good hive structure is determined by the environment. A hive that has good thermal insulation, is easy to manage and protects against pests & predators is one such example. When beekeepers optimise their hive design, it puts less strain on the bees, who can focus on brood rearing and honey production. If you want to know about the consequences of poor hive insulation, then read about my winter 2024 hive deaths.

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Footnotes

1. Other box types exist, like the deep and jumbo supers, and many more varieties depending on your location To determine which box style suits you best, I’ve produced the flow chart below. ↩︎
2. Check whether local regulations permit them. Log hives do not have removable frames, which makes brood inspection a destructive process. For that reason, they are forbidden in Australia, (NSW Biosecurity Regulation 2017, Clause 84(1)). ↩︎