How to inspect a beehive: external and internal checks

A hive inspection combines observations outside the hive with checks of the colony inside. Entrance activity, dead bees, debris, odour and sound can flag problems, but they do not establish a diagnosis on their own. Inspect apparently healthy colonies before suspect ones, practise hygiene between colonies, and arrange specialist help when the signs suggest disease.

In this guide

• good practices for the visit;
• the external inspection and its observation chart;
• the internal inspection and what to assess in each frame;
• the observation chart for what you see inside.

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Good practice before an inspection

An apiary visit begins before you arrive. Consider the weather over the previous few days and what is flowering nearby. Looking over the final kilometre or two is useful, but bees may forage farther afield. A varied forage supply is valuable; counting four or five flowering species does not, by itself, prove that the colony has a complete diet or enough food.

At the apiary, put on suitable protective clothing and observe the entrances. Record the identity of any hives showing unusual signs so you can assess them separately. Work from apparently healthy colonies towards suspect ones and clean tools and gloves between colonies. Do not transfer combs, bees or food from a suspect colony to another. If you suspect a notifiable disease, contact the relevant bee-health authority promptly rather than continuing routine manipulations.

External inspection: what the hive entrance reveals

Observe bee behaviour around the hive and at the entrance, including fighting, crawling and unusual flight. Note sound, odour, dead bees and material being removed, such as larvae, pupae, wax or pollen. Interpret these observations against weather, time of day, season and earlier records; entrance activity alone cannot confirm queen status or freedom from disease.

Track weight changes since the previous visit, while accounting for added supers, feeding, harvests and other equipment changes. The trend can help assess stores and nectar intake. It does not directly measure bee numbers, and weighing does not replace brood and disease checks.

External signs: possible explanations

Observation	Possible interpretation and next step
Many dead bees at the entrance	Possible causes include pesticide exposure, disease, starvation and weather-related losses. Record the timing and seek prompt advice on suitable samples; the pile alone does not identify the cause.
Bees fighting at the entrance	May indicate robbing, especially with intruders trying to enter at cracks. Distinguish it from normal guard activity.
Drones expelled or found dead	Can occur during seasonal contraction or a dearth. Assess the season and food supply; it is not specific to one condition.
Shiny, hairless, trembling or crawling bees	Paralysis virus is one possible explanation, but appearance alone is not confirmation. Seek bee-health advice or laboratory testing.
Hard, chalk-like brood mummies	Suggest chalkbrood; examine brood and confirm uncertain findings.
Dead larvae carried out	Brood removal can follow disease, chilling, nutritional stress or other damage. Examine the remaining brood and its pattern.
Pollen being brought in	Shows active pollen collection. It often accompanies brood rearing, but does not prove that a queen is present or the colony is healthy.
A cloud of bees flying in front of the hive	May be orientation flights or a swarm. Look at the scale, duration, direction and whether a cluster forms before deciding.
Restless bees on the landing board	Non-specific behaviour. Do not diagnose queenlessness from one nervous or disoriented bee.
Mouldy pollen or other mouldy debris	May indicate moisture and unused comb or stores. Assess colony strength, water ingress and hive condition, not ventilation alone.
Heavy brown faecal staining	Dysentery can be associated with confinement or unsuitable food. Colour and consistency are not a reliable disease test.
Dark or watery faecal staining	Nosema may be among the concerns, but staining does not diagnose it and its absence does not rule it out. Follow laboratory advice for testing.
Soft, discoloured larval remains	Possible brood disease or damage from chilling, starvation or pests. The appearance needs assessment in context; do not select a treatment from this sign alone.

Internal inspection: opening the hive and reading the frames

Examining the brood nest provides important evidence about queen activity, brood development, food and colony condition. First assess adult bee coverage, then make enough space to lift frames gently without rolling bees or injuring the queen. Keep frames over the hive where practical and out of prolonged sun, wind or cold. Inspect the frames needed for the purpose of the visit; a thorough disease examination requires a clear view of brood and comb.

When examining the frames, assess:

• Look for eggs, young larvae and a developing worker-brood pattern. A queen usually lays one egg per cell, but use several observations together to assess queen status and performance.
• Comb condition, including damaged cells, abnormal brood remains and excessive deterioration.
• Brood pattern, larval appearance and cappings, interpreted in the context of season, brood age and colony history.
• Honey and pollen stores, especially during dearths and before winter, to decide whether supplementary feeding is needed.
• Sufficient space for the queen to lay and for storing honey and pollen.
• Any queen cells: record their stage and context. They may reflect swarming, supersedure or emergency queen rearing; do not remove them automatically.

Internal signs: possible explanations

Observation	What to check before drawing a conclusion
No eggs or brood	Check season, recent swarming or queen replacement, food and colony history. Queenlessness or a failing queen are possibilities, not the only explanations.
Deformed wings; or worn, ragged wings	Deformed wing virus is associated with Varroa. Worn wing edges alone may reflect age or injury. Monitor mites rather than diagnosing an infestation level by sight.
Several eggs in cells or drone brood in worker cells	Investigate laying workers or a drone-laying queen. A new queen may occasionally lay multiple eggs; check the pattern, egg position and subsequent brood.
Patchy brood pattern	Possible contributors include brood disease, Varroa-associated damage, queen problems, nutrition or other stress. Recently emerged cells and nectar stored among brood can also create gaps; examine larvae and cappings, not the pattern alone.
Two queens in one colony	Temporary coexistence can occur during supersedure. Do not assume that either queen must be removed without assessing the colony.
Small, compact brood area	May reflect a recently laying queen, season, restricted space or a limited workforce. Compare with stores, available cells and earlier observations.
Unusual foul odour or abnormal brood	Foulbrood is a concern, but smell neither confirms it nor distinguishes American from European foulbrood. Suspect brood needs prompt expert assessment; prevent transfers and follow local reporting requirements.

Build sound judgement

Develop evidence-based judgement from careful observation, records and training. If advice does not fit what you see, investigate before acting. Equally, do not let confidence or habit replace testing or advice from an experienced beekeeper, bee inspector or veterinarian when a problem is unclear.

Experience improves your ability to recognise changes in a colony. Record what you observed, what you did and what needs checking next time. Learning from the bees means observing their response and checking your assumptions, not treating any single sign as proof.

Frequently asked questions

Continue reading

• Where is the queen? How to find her during an inspection.
• Hygienic management in hives, the rationale behind the inspection order.
• Diagnosing Varroa, when the signs point in that direction.
• Hive monitoring, to track weight without opening the hive.

Further guidance: the National Bee Unit’s Handling and examining a colony of bees (2025, hosted by SRUC), and UF/IFAS guidance on recognising European foulbrood. For an example of official disease reporting, see UK bee-health guidance; follow the rules and services in your own country. The original diagram labels and some linked shop and related blog pages remain in Spanish. This English edition clarifies the limits of diagnosis from visible signs.