Honeybee

A honeybee on its own is a fragile insect that lives about six weeks. A honeybee colony is something else — a self-regulating society of tens of thousands that builds precise architecture, controls its own temperature, votes on where to live, and passes navigational directions between members by dancing.

Overview

The western honeybee is native to Europe, Africa, and western Asia and has been carried by beekeepers to every continent except Antarctica. In the wild it nests in tree hollows and rock cavities; in managed beekeeping it lives in stacked wooden boxes. Either way, the unit that matters is the colony, and a lone bee cannot survive for long outside it.

The colony

A summer colony holds one queen, 20,000 to 80,000 sterile female workers, and, seasonally, a few hundred male drones.

• The queen mates only once, on a single flight during which she stores sperm from a dozen or more drones for the rest of her life. From then on she does nothing but lay eggs — up to 2,000 a day — while workers feed and groom her and spread her pheromones, which hold the colony’s identity and behaviour together.
• Workers move through a sequence of jobs as they age: cleaning cells, feeding larvae, building wax comb, processing nectar into honey, guarding the entrance, and finally, for the last weeks of life, foraging.
• Drones exist only to mate. They cannot sting, forage, or feed themselves, and in autumn the workers stop feeding them and push them out to die.

The colony behaves as a superorganism: it shivers its flight muscles to keep the brood nest at a steady 35 °C in winter and fans water to cool it in summer, and when it grows too large it splits, half the bees leaving with the old queen in a swarm while scouts perform dances to reach a collective decision on a new home.

Navigation and the waggle dance

Foraging bees travel up to 5 km from the hive and navigate using the sun as a compass, correcting for its movement across the sky with an internal clock, and reading polarised light on cloudy days.

When a forager finds a good patch of flowers, she communicates its location to the hive with the waggle dance — a figure-eight walk on the vertical comb whose angle encodes direction relative to the sun and whose duration encodes distance. It is one of the only known examples of an animal giving another abstract, symbolic directions to a place it has never been.

Honey, wax, and pollination

Bees collect nectar for energy and pollen for protein. Nectar is carried home in a special stomach, mixed with enzymes, and fanned until enough water evaporates to make honey, which stores indefinitely and feeds the colony through winter. Workers secrete beeswax from glands on the abdomen to build the hexagonal comb.

In the course of visiting flowers, honeybees pollinate a large share of the world’s flowering plants, including many crops — a service worth hundreds of billions of dollars a year to agriculture.

Threats to bee health

The honeybee is not a threatened species, but keeping colonies alive has become steadily harder. The main pressures are:

• The Varroa mite, a parasite that feeds on bees and their brood and transmits deforming viruses; it is now nearly worldwide and is the single biggest driver of colony losses.
• Pesticides, especially neonicotinoids, which impair foraging, navigation, and immunity even at sub-lethal doses.
• Poor nutrition from large monoculture landscapes that offer a brief glut of one crop and then nothing.
• Habitat loss of the hedgerows, meadows, and wild flowers that provide season-long forage.

The same pressures fall even harder on the thousands of species of wild bees, many of which have no beekeeper to prop them up.