In a natural nest, “bee space” is the gap that honey bees leave open, allowing them to move freely within their hive. Typically, bees avoid filling this space with propolis or comb. This phenomenon becomes evident when a wild colony is removed from a structure, like a tree or building.
The concept of bee space was harnessed by Rev. Lorenzo Langstroth, who applied it to create “moveable frames” within hives. This innovation simplified hive inspections and has become a staple of modern beekeeping. Although it’s sometimes said that Langstroth “discovered” or “invented” bee space, it was the bees who first “designed” this feature in their natural habitats; Langstroth merely adapted it to practical use.
Bee space is also critical in top-bar hives, where it prevents bees from attaching their comb to the hive walls.
Generally accepted dimensions for bee space range between 4.5 mm and 8 mm, though there is some variability in reported measurements. However, bee space isn’t truly flexible. It consists of two main bands: one measuring around 5.3 mm ± 0.5 mm and another at 9 mm ± 1 mm. These variations arise depending on whether bees work individually or require enough space to move back-to-back.
Here’s a breakdown of how bees utilize different gap sizes:
- Below 4 mm: Too narrow for regular bees, this space is typically filled with propolis or a wax-propolis mixture, potentially mixed with pollen for porosity or light transmission.
- 4.3 mm: Standard in European queen excluders.
- 5 mm: Useful in pollen strippers, as worker bees can pass but pollen is stripped from their legs.
- 5.2–5.4 mm: Ideal for drone exclusion; only workers and queens can pass through.
- 6 mm: The smallest gap bees leave between adjacent combs outside of clustering areas, allowing for airflow and humidity control.
- 7 mm: Not widely used by bees, but some beekeeping setups utilize this space to minimize wax buildup.
- 8 mm: A mid-range bee space often preferred by hive designers.
- 9 mm: Common between capped brood areas, where it allows two layers of bees to work back-to-back.
- More than 9 mm: Typically results in “brace comb,” as bees seek to close the excess space with additional comb.
For hive design, gaps up to 10 mm might be used to accommodate natural wood shrinkage, ensuring frames remain functional even with minimal maintenance. Larger gaps, such as 28–31 mm between the bottom of frames and the hive floor, mimic the space found in wild hives, where bees generally avoid adding comb.