Honey bee anatomy
A honey bee is a flying nectar processor with a comb-building factory attached. Almost every structure on it maps directly onto a job the colony needs done.
The three body sections
- Head — eyes, antennae, mouthparts and the brain. The sensory and feeding end.
- Thorax — the engine. Both pairs of wings and all six legs attach here, powered by flight muscles that also generate heat.
- Abdomen — the processing and defence end, holding the honey stomach, the wax glands, the scent gland and the sting.
The head
| Structure | What it is | What it does |
|---|---|---|
| Compound eyes | Two, of about 6,900 facets in a worker | Motion detection, colour vision into the ultraviolet |
| Ocelli | Three simple eyes on top of the head | Detect light intensity; used for orientation and horizon |
| Antennae | Segmented, with thousands of sensory pits | Smell, touch, taste, humidity, carbon dioxide |
| Mandibles | Smooth jaws | Working wax, grooming, gripping, chewing out of the cell |
| Proboscis | A folding tongue | Drawing nectar; the length decides which flowers are usable |
The antennae deserve emphasis. A bee's world is chiefly chemical, and an antenna carries several thousand sensory structures. Bees detect flower scent, nestmate identity, queen pheromone and the state of the brood almost entirely through them.
The thorax
Two pairs of wings, hooked together in flight by a row of hooks so that they act as one surface, driven indirectly — the muscles deform the thorax rather than pulling on the wings, which is what allows a wingbeat of around 230 per second.
Those same flight muscles are also the colony's heater. A bee can decouple her wings and shiver the muscles to generate heat, which is how the cluster warms in winter and how the brood nest is held at 34-35 °C.
The hind legs carry the corbicula — the pollen basket — a smooth concave area fringed with hairs into which packed pollen is pressed. Only honey bees, bumblebees, stingless bees and orchid bees have one; most bees carry pollen dry in a brush of hairs instead.
The abdomen
| Structure | What it does |
|---|---|
| Honey stomach | A crop holding around 40 mg of nectar, separate from the digestive gut |
| Wax glands | Four pairs on the underside, secreting wax scales in bees of about 12-18 days old |
| Nasonov gland | Releases an orientation pheromone; the bee stands and fans to guide others home |
| Sting | A modified ovipositor, barbed in workers, with a venom sac attached |
| Spiracles and tracheae | Air enters through the body wall; bees have no lungs |
What is different in the other castes
A queen has a longer abdomen, a smooth unbarbed sting she can use repeatedly, and no pollen baskets or wax glands — she does no foraging and builds nothing. A drone is bulkier with enormous eyes that meet on top of his head, has no sting at all, and no pollen-carrying structures. His eyes are the giveaway, and they exist because his single job is to find a queen in flight.
The gut: carrying and digesting are different jobs
The most misunderstood organ in the bee is the one called a stomach. The crop, or honey stomach, is an expandable sac at the end of the oesophagus, in front of the gut proper. A forager fills it with nectar or water and, back at the nest, brings most of the load up again to pass to other bees. Between the crop and the midgut sits a valve, the proventriculus, which lets through only what the bee itself needs and strains out pollen grains. Digestion happens beyond it, in the midgut; waste is filtered from the blood by the Malpighian tubules, and most of the worker's specialised gut bacteria live further on still, in the ileum and rectum.
Breathing, blood and the fat body
A bee breathes through openings along its sides, the spiracles, which lead into branching tubes that carry air straight to the tissues; pumping movements of the abdomen help ventilate air sacs. Its circulation is open: a tubular heart along the back pumps haemolymph forward to the head, and it washes back through the body cavity carrying nutrients, hormones, waste and immune cells — but not oxygen.
Lining the abdomen is the fat body, a tissue with no single counterpart in our anatomy. It stores energy as glycogen and fat, makes vitellogenin and other proteins carried in the haemolymph, and takes part in immunity. Calling it the bee's liver captures one of its jobs. It is also what Varroa mites eat: experiments published in 2019 found that the mite feeds primarily on fat body tissue, not on haemolymph as had long been assumed.
Part by part, and caste by caste
| Part | Where | System | What it does | A common misreading |
|---|---|---|---|---|
| Antennae | Head | Senses | Jointed feelers carrying thousands of sensilla for smell, taste, touch, humidity, temperature and carbon dioxide. An organ at the antenna's base (Johnston's organ) senses the antenna's own movement, including the air currents of a dancing bee. | — |
| Compound eyes | Head | Senses | Two eyes of thousands of facets (ommatidia) each, giving wide-angle, low-resolution vision that is fast at detecting motion and sensitive to ultraviolet, blue and green light and to the polarisation of skylight. | — |
| Ocelli | Head | Senses | Three simple eyes on top of the head that register light intensity rather than images, used in flight and in judging light levels. | — |
| Brain | Head | Nervous system | About a million neurons. The mushroom bodies are central to learning and memory; large optic and antennal lobes process vision and smell. | — |
| Mandibles and proboscis | Head | Feeding | The mandibles chew, carry, groom and shape wax; the proboscis is a folding tongue that draws up nectar, honey and water, and passes food in mouth-to-mouth exchange. | — |
| Hypopharyngeal and mandibular glands | Head | Glands | In nurse workers the hypopharyngeal glands make the protein-rich part of brood food, and the mandibular glands add lipid components. In foragers the hypopharyngeal glands shrink and produce sugar-converting enzymes added to nectar. | — |
| Flight muscles | Thorax | Movement | Indirect flight muscles fill the thorax and drive the wings by distorting it. With the wings uncoupled, the same muscles shiver to make heat — which is how a colony warms its brood and its winter cluster. | — |
| Wings and legs | Thorax | Movement | Two pairs of wings hooked together in flight; six legs that walk, groom and clean the antennae through a notch on the forelegs. | — |
| Crop (honey stomach) | Abdomen | Carrying food | An expandable sac at the end of the oesophagus, in front of the gut proper. It holds nectar or water for the flight home and for passing to other bees; a valve, the proventriculus, controls what moves on into the midgut and strains out pollen grains. | Nectar is digested in the honey stomach. — The crop is a carrying tank before the gut proper. Enzymes from the head glands are mixed into the nectar, but the bee's own food is digested further on, in the midgut, only after passing the proventriculus. |
| Midgut | Abdomen | Digestion | The true stomach, where food — including pollen — is digested and absorbed into the haemolymph. | — |
| Hindgut (ileum and rectum) | Abdomen | Digestion | Where most of the worker's specialised gut bacteria live. The rectum stores waste, and can hold it for months in winter until a cleansing flight. | — |
| Malpighian tubules | Abdomen | Excretion | Fine tubules joining the gut where midgut meets hindgut. They draw waste from the haemolymph — the insect equivalent of kidneys, not lungs or liver. | — |
| Spiracles, tracheae and air sacs | Throughout the body | Breathing | Air enters through openings (spiracles) along the thorax and abdomen and travels through branching tubes (tracheae) direct to the tissues, with air sacs that pumping movements of the abdomen help ventilate. | Bees breathe with lungs, through the mouth. — There are no lungs. Oxygen reaches the tissues through the tracheal tubes, not through the blood. |
| Dorsal vessel and haemolymph | Throughout the body | Circulation | An open circulation: a tubular heart along the back pumps haemolymph forward through the aorta, and it then bathes the organs. Haemolymph carries nutrients, hormones, waste and immune cells — but not oxygen, which the tracheae deliver. | Varroa mites suck bees' blood. — Experiments published in 2019 found that Varroa feeds primarily on fat body tissue, not on haemolymph. |
| Fat body | Abdomen | Metabolism and storage | A loose tissue lining the body cavity that stores energy as glycogen and fat and releases it on demand, makes vitellogenin and other haemolymph proteins, and takes part in immunity and in breaking down foreign compounds. | The fat body is the bee's liver. — It shares some jobs with a liver, but it is also the main energy store, a protein factory and part of the immune system — no single vertebrate organ matches it. |
| Wax glands | Abdomen | Glands | Four pairs of glands on the underside of the abdomen that secrete wax as thin scales, which the bee removes with her legs and works with her mandibles into comb. | — |
| Sting and venom sac | Abdomen | Defence | A modified egg-laying tube with two lancets and a venom sac. Alarm pheromone released from the sting chamber marks a target and recruits other defenders. | — |
| Reproductive organs | Abdomen | Reproduction | Ovaries and a sperm store (spermatheca) in females; testes and an eversible endophallus in males. | — |
Worker anatomy unless a caste is named; how the castes differ is in the next table.
Checked 2026-10-31 against: The Biology of the Honey Bee (Harvard University Press, 1987); The chemoreceptor superfamily in the honey bee, Apis mellifera: expansion of the odorant, but not gustatory, receptor family (Genome Research, 2006); The Mind of a Bee (Princeton University Press, 2022); The honeybee as a model for understanding the basis of cognition (Nature Reviews Neuroscience, 2012); Pheromone communication in the honeybee (Apis mellifera L.) (Journal of Chemical Ecology, 2005); Honeybee colony thermoregulation – regulatory mechanisms and contribution of individuals in dependence on age, location and thermal stress (PLoS ONE, 2010); The Bees of the World (Johns Hopkins University Press, 2007); Gut microbial communities of social bees (Nature Reviews Microbiology, 2016); Varroa destructor feeds primarily on honey bee fat body tissue and not hemolymph (Proceedings of the National Academy of Sciences 116(5):1792–1801 (Ramsey and colleagues), 2019); Insect fat body: energy, metabolism, and regulation (Annual Review of Entomology 55:207–225 (Arrese and Soulages), 2010); The gene vitellogenin has multiple coordinating effects on social organization (PLOS Biology 5(3):e62 (Nelson, Ihle, Fondrk, Page and Amdam), 2007); Beeswax: Production, Properties, Composition and Control (Bee Product Science, 2016); The Lives of Bees: The Untold Story of the Honey Bee in the Wild (Princeton University Press, 2019).
| Worker | Queen | Drone | |
|---|---|---|---|
| Egg and genetics | A fertilised egg: female, with a mother and a father. | A fertilised egg, the same as a worker's — caste is set by how the larva is fed. | An unfertilised egg: male, with one set of chromosomes, all from his mother. He has no father but does have a grandfather, through his mother. |
| What makes a bee female | Two different versions (alleles) of the sex-determining gene csd. A fertilised egg with two identical versions develops as a diploid male, which does not reproduce. | As for workers. | One copy of csd, from an unfertilised egg. |
| Larval diet | Glandular food from nurses at first, then a diet that includes pollen and honey; less food, and different in composition, from early in larval life. | Royal jelly in large quantity throughout larval life. Diet quantity and composition act on the larva's development, including through DNA methylation; no single protein has been shown to make a queen. | Fed by workers on a diet differing from both female castes. |
| Egg to adult | About 21 days. | About 16 days. | About 24 days. |
| Adult life | A few weeks in the active season; several months for the long-lived workers reared before winter. | Several years in many colonies, though beekeepers often replace queens sooner. | Weeks to a few months; most are expelled as forage fails at the end of the season. |
| What she or he does | Everything else: cleaning, nursing, building, guarding, foraging — in a sequence linked to age but shifted by what the colony needs. | Lays the colony's eggs and is the main source of queen pheromone; she does not rule. | Mates with queens from other colonies; does no colony work. |
| Body equipment | Pollen baskets, wax glands, brood-food glands, barbed sting, long tongue. | Long abdomen with large ovaries and a sperm store; smooth sting; no pollen baskets or wax glands. | Large eyes and thirteen-segment antennae; no sting, pollen baskets or wax glands. |
| Antennae | Twelve segments; the main organs for floral and colony odours. | Twelve segments. | Thirteen segments, with many more olfactory sensilla — used to find queens by their pheromone in flight. |
| Compound eyes | Several thousand facets per eye. | The smallest eyes of the three castes. | Much larger eyes meeting at the top of the head — suited to spotting a queen against the sky. |
| Ocelli | Present. | Present. | Present, set among the enlarged compound eyes. |
| Brain | Mushroom bodies grow as a worker begins foraging. | Not separately described in the sources read. | Not separately described in the sources read. |
| Mandibles and proboscis | The longest tongue of the three castes, used in foraging and food exchange. | Shorter tongue; she is fed by workers. | Short tongue and small mandibles; drones are fed by workers or take honey from cells. |
| Hypopharyngeal and mandibular glands | Both glands developed; their output changes with the job she is doing. | Mandibular glands produce queen mandibular pheromone; hypopharyngeal glands are not developed. | Neither gland is developed for feeding others. |
| Flight muscles | Used in flight and in heating brood. | Used on mating flights and when a colony swarms. | Large; used on mating flights to congregation areas. |
| Wings and legs | The hind legs carry pollen baskets (corbiculae), where pollen and resin are packed for the flight home. | No pollen baskets. | No pollen baskets. |
| Crop (honey stomach) | Carries nectar and water loads; her own fuel is drawn from it through the valve. | Present; she is fed by workers rather than foraging. | Present; drones do not forage. |
| Midgut | Digests pollen, the colony's protein source, in young nurse bees especially. | Digests the glandular food workers feed her. | Digests food from workers and from cells. |
| Hindgut (ileum and rectum) | Colonised by a characteristic bacterial community in her first days, acquired from nestmates. | Not separately described in the sources read. | Not separately described in the sources read. |
| Fat body | Large in nurse and winter bees, which carry high vitellogenin; smaller in foragers. | Supplies vitellogenin for egg production. | Not separately described in the sources read. |
| Wax glands | Most active in young adult workers, and when the colony needs comb; scales are chewed and shaped before building. | Absent. | Absent. |
| Sting and venom sac | Barbed lancets: in thick-skinned targets the sting, venom sac and muscles tear away and keep pumping, and the bee dies. | Smooth, curved sting used chiefly against rival queens; she can withdraw it and sting again. | No sting. |
| Reproductive organs | Small ovaries; without a queen some workers lay unfertilised eggs, which develop as drones. | Large ovaries; she mates with many drones on a few flights early in life and stores their sperm for years, fertilising eggs as she lays them. | Mates once, in flight, and dies doing so. |
'Not separately described' means the sources read do not say — not that the caste lacks the part.
Checked 2026-10-31 against: The Biology of the Honey Bee (Harvard University Press, 1987); The gene csd is the primary signal for sexual development in the honeybee and encodes an SR-type protein (Cell 114(4):419–429 (Beye and colleagues), 2003); Nutritional control of reproductive status in honeybees via DNA methylation (Science 319:1827–1830 (Kucharski, Maleszka, Foret and Maleszka), 2008); Royalactin is not a royal making of a queen (Nature 537:E10–E12 (Buttstedt, Ihling, Pietzsch and Moritz), 2016); The Lives of Bees: The Untold Story of the Honey Bee in the Wild (Princeton University Press, 2019); Regulation of division of labor in insect societies (Annual Review of Entomology 37:637–665 (Robinson), 1992); The chemoreceptor superfamily in the honey bee, Apis mellifera: expansion of the odorant, but not gustatory, receptor family (Genome Research, 2006); The Mind of a Bee (Princeton University Press, 2022); The honeybee as a model for understanding the basis of cognition (Nature Reviews Neuroscience, 2012); Pheromone communication in the honeybee (Apis mellifera L.) (Journal of Chemical Ecology, 2005); Honeybee colony thermoregulation – regulatory mechanisms and contribution of individuals in dependence on age, location and thermal stress (PLoS ONE, 2010); The Bees of the World (Johns Hopkins University Press, 2007); Gut microbial communities of social bees (Nature Reviews Microbiology, 2016); Insect fat body: energy, metabolism, and regulation (Annual Review of Entomology 55:207–225 (Arrese and Soulages), 2010); The gene vitellogenin has multiple coordinating effects on social organization (PLOS Biology 5(3):e62 (Nelson, Ihle, Fondrk, Page and Amdam), 2007); Varroa destructor feeds primarily on honey bee fat body tissue and not hemolymph (Proceedings of the National Academy of Sciences 116(5):1792–1801 (Ramsey and colleagues), 2019); Beeswax: Production, Properties, Composition and Control (Bee Product Science, 2016).
The castes are not three sizes of the same bee. A drone comes from an unfertilised egg and carries one set of chromosomes, all from his mother; he has no father but does have a grandfather. A queen and a worker come from identical fertilised eggs, and what separates them is how the larva is fed — the quantity and composition of its diet acting on its development, including through DNA methylation, rather than any single substance in royal jelly. The sex itself is set by one gene, csd: two different versions make a female, one makes a male, and two identical versions make a diploid male that does not reproduce.
Sources
- Gut microbial communities of social bees — Nature Reviews Microbiology (2016) · Peer-reviewed article Link
- Insect fat body: energy, metabolism, and regulation — Annual Review of Entomology 55:207–225 (Arrese and Soulages) (2010) · Peer-reviewed article Link
- Varroa destructor feeds primarily on honey bee fat body tissue and not hemolymph — Proceedings of the National Academy of Sciences 116(5):1792–1801 (Ramsey and colleagues) (2019) · Peer-reviewed article Link
- The gene vitellogenin has multiple coordinating effects on social organization — PLOS Biology 5(3):e62 (Nelson, Ihle, Fondrk, Page and Amdam) (2007) · Peer-reviewed article Link
- The gene csd is the primary signal for sexual development in the honeybee and encodes an SR-type protein — Cell 114(4):419–429 (Beye and colleagues) (2003) · Peer-reviewed article Link
- Nutritional control of reproductive status in honeybees via DNA methylation — Science 319:1827–1830 (Kucharski, Maleszka, Foret and Maleszka) (2008) · Peer-reviewed article Link
- Royalactin is not a royal making of a queen — Nature 537:E10–E12 (Buttstedt, Ihling, Pietzsch and Moritz) (2016) · Peer-reviewed article Link
- Regulation of division of labor in insect societies — Annual Review of Entomology 37:637–665 (Robinson) (1992) · Peer-reviewed article Link
- The Lives of Bees: The Untold Story of the Honey Bee in the Wild — Princeton University Press (2019) · Monograph
- The Biology of the Honey Bee — Harvard University Press (1987) · Textbook
- The Bees of the World — Johns Hopkins University Press (2007) · Textbook
How sources are selected and weighted is set out in the sources and evidence policy.
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