How a honey bee colony works

The superorganism idea

A honey bee colony is frequently described as a superorganism, and the analogy holds better than most. It regulates its own temperature within a degree. It has a circulatory system in the form of food sharing between individuals. It has an immune response, both individual and social. It reproduces as a unit, by swarming, rather than through individual bees.

And it makes decisions no individual bee makes. No bee compares two nest sites; no bee decides how to divide the workforce; no bee knows how much honey is in store. All of those outcomes emerge from local behaviour.

The mechanisms

The nectar-acceptance mechanism is a particularly good illustration. A returning forager cannot see how full the hive is. What she experiences is how long she waits to hand over her load. A short wait means receivers are idle and the colony has capacity; a long wait means it does not. She adjusts her dancing accordingly, and the colony's foraging effort tracks its storage capacity with nobody measuring either.

The colony as a unit of selection

Because workers are sterile, natural selection acts largely on the colony rather than on the individual. A worker's genetic interests are served by the colony reproducing, which is why self-sacrifice — a barbed sting that kills her, or evicting her own brothers in autumn — is not the puzzle it first appears.

This is also why the colony, not the bee, is the meaningful unit for most purposes. A single honey bee cannot survive alone for long, cannot reproduce, and cannot thermoregulate. It is closer to a cell than to an animal.

The annual cycle

1. 1Late winterBrood rearing resumes on stored pollen, weeks before there is anything to forage. The colony is betting on spring.
2. 2Spring build-upPopulation rises steeply; the colony converts stores and early forage into bees.
3. 3Swarming seasonIf congestion and pheromone dilution coincide, the colony reproduces by dividing.
4. 4SummerPeak population, up to sixty thousand bees, and the main honey flows.
5. 5Late summerDrones evicted, winter bees reared, stores consolidated.
6. 6WinterCluster formed. No foraging, no brood for a period, and a slow burn through stores.

What this means for beekeeping

Almost every beekeeping intervention is an attempt to work with these mechanisms rather than against them. Adding a super gives receiver bees somewhere to put nectar and keeps foragers dancing. Splitting a colony pre-empts a swarming decision the colony was about to make. Requeening resets the pheromone signal. Understanding the mechanism is the difference between managing a colony and interfering with one.