Monthly Beehive Inspection & Colony Health

ContextWhat you see at the entrance tells you a great deal before you invest time opening the hive. Normal foraging traffic is directional: bees leave briskly and return carrying pollen in their corbiculae (pollen baskets on the hind legs). Bees milling at the entrance in large, undirected numbers, or fighting and chasing each other, are signs of robbing behavior — in that case, you should reduce the entrance and not open the hive at all until the situation resolves. Orientation flights look like young bees hovering in place, facing the hive entrance — normal, especially on calm afternoons in warm months. Fanning bees at the entrance during hot weather are thermoregulating, not being aggressive.

ContextSome dead bees near the entrance are entirely normal — summer workers live 4–6 weeks and die constantly. A cup or more of dead bees piled in front of the hive, especially with no visible injury, is a red flag for pesticide exposure, often from nearby agricultural spraying. Bees found dead with extended tongues (protruding from the mouthparts) are a classic pesticide kill indicator. A sweet, fermenting, almost barnyard-like odor rising from the bottom board can suggest American Foulbrood (AFB), one of the most serious bacterial diseases in beekeeping. Note any chewed wax or webbing debris on a screened bottom board — these are indicators of small hive beetle or wax moth activity inside.

ContextWoodpecker damage — irregular gouges through the outer wall — is most common in late winter when woodpeckers target vibrations from the winter cluster. Any breach that exposes comb invites robbing and weather damage. Run your hand under the joint where the hive body meets the bottom board and feel for soft, punky wood, which signals moisture intrusion. A hive sitting level on its stand sheds rain correctly; one tilting forward pools moisture in the interior. Check that the outer cover lies flat and the inner cover sits flush — gaps encourage mice in winter and beetles and moths in summer.

ContextAfter lifting out the first frame, count how many frames have bees coating both sides. A healthy mid-spring colony in a standard 10-frame deep should cover at least 6–8 frames. A colony covering only 3–4 frames during peak season is considered weak and may struggle to thermoregulate brood, defend against pests, and bring in sufficient nectar. Weakness alone is not a crisis — it can be addressed by combining colonies, donating a frame of emerging brood from a stronger hive, or re-queening — but you cannot make that decision without a population count each visit. Record your frame-coverage number and compare it with last month's figure.

ContextFinding the queen herself is ideal but not always necessary on every inspection. Queens are noticeably larger, with an elongated abdomen, and are typically surrounded by an attendant retinue of workers who face toward her and groom her. Start your search on the frames with the most active brood, usually in the center of the lower box. If you cannot spot her after scanning 3–4 frames, look for fresh eggs — their presence confirms she was laying within the past 72 hours, which is sufficient for most routine assessments. Marking your queen with a color-coded paint pen (international coding: white for years ending in 1 or 6, yellow 2 or 7, red 3 or 8, green 4 or 9, blue 5 or 0) reduces the average time to locate her from ten minutes to thirty seconds.

ContextHold the frame with your back to the sun so light angles down into the cells at an oblique angle — eggs are approximately 1.5mm long and nearly translucent. Tilt the frame and look for a tiny white line standing upright at the base of an apparently empty cell. A freshly laid egg is perfectly vertical; a two-day egg leans slightly; a three-day egg is nearly horizontal and beginning to look like a tiny larva curled at the cell bottom. The presence of eggs is the most reliable queen-activity confirmation available — more reliable than spotting the queen herself, because a colony that has lost its queen can still appear to have a healthy brood cycle for up to three weeks while the new-queen timeline begins. If you find no eggs across multiple frames of open comb, that absence is meaningful and warrants investigation.

ContextA healthy brood frame has a compact, solid oval or football-shaped pattern of capped cells with very few random empty gaps. Scattered brood — commonly called a 'shotgun pattern,' where capped cells are interspersed with many empty holes — is a warning sign. It can result from a failing queen, disease causing workers to uncap and remove infected larvae, or laying workers producing unfertilized eggs that fail to develop (multiple eggs per cell, or eggs positioned on the cell wall rather than the base, are key identifiers). Examine capped cell surfaces carefully: healthy worker brood has a slightly convex, dry, tan, felt-textured cap. Sunken, greasy, or perforated cappings with a foul odor — especially spreading in a progressive pattern — are the hallmarks of American Foulbrood. If you suspect AFB, insert a toothpick into a discolored capped cell and withdraw it slowly: healthy brood removes cleanly; AFB-infected brood ropes out in a stringy brown thread. AFB is a reportable disease in most U.S. states and many countries — notify your state apiarist immediately if confirmed.

ContextThe alcohol wash is the most accurate field method for varroa monitoring and should be done every inspection during the active season, not only when you suspect a problem. Collect roughly half a cup of bees from a brood frame — avoiding the queen — by shaking directly into a wide-mouth jar. Aim for about 100–150 bees; reduce to your target count if needed. Add 70% isopropyl alcohol, seal the jar, and shake vigorously for 60 seconds. Pour the contents through a fine mesh strainer into a white pan or tray, then rinse with a little more alcohol. Count the mites that settled in the pan. Your infestation percentage is: (mite count ÷ number of bees) × 100. Record this alongside the date and your current brood volume estimate.

ContextThe widely cited treatment threshold is 2–3% (2–3 mites per 100 bees), but threshold interpretation depends on season. A count of 2% in July — when the colony is building toward its fall population peak and raising the winter bees that will carry it through to spring — carries far more urgency than a 2% count in late April during a rapid brood-rearing expansion that will naturally dilute the mite-to-bee ratio. Varroa reproduce exclusively inside capped brood cells, so colonies with heavy brood volumes in summer will see counts climb fastest. Write down your mite percentage, the date, and an estimate of brood volume (frames of capped worker brood). A single data point is informative; three consecutive inspections showing a rising trend is the signal that changes a decision.

ContextVarroa mites reproduce at roughly 7–10 times the rate in drone brood compared to worker brood, making drone cells a useful early indicator of mite pressure. Drone cells are slightly larger and have a distinctively domed, bullet-shaped cap compared to the flatter profile of worker cappings. Use the hooked end of your hive tool to uncap a cluster of drone cells. Inside a healthy drone cell you will find a pale cream-colored pupa. If you see small, reddish-brown oval mites (about 1.5mm) on the pupa or clinging to the cell walls, your colony has detectable mite pressure. This is a supplement to — not a substitute for — the alcohol wash; it can detect presence but cannot produce a percentage and misses moderate infestations entirely.

ContextThe quickest field method is 'hefting': lift the back of the hive body slightly and judge its weight. A fully loaded 10-frame deep with honey weighs 80–90 lbs; a hive that lifts easily and feels hollow is a concern. For a more precise estimate during inspection, count frames where more than half the comb is capped with honey or heavy with translucent nectar. A colony should maintain a minimum of two full frames of capped honey at all times during the active season, and significantly more heading into fall. In early spring, before the first major nectar flow, depletion of winter stores is one of the leading causes of colony death — colonies that appeared healthy in February can starve out in two to three weeks during a cold snap in March.

ContextPollen — stored as fermented bee bread in cells immediately adjacent to the brood nest — is the colony's only protein source and is essential for raising healthy larvae. Look for a visible arc or ring of multicolored pollen cells (yellow, orange, red, tan, green, and even purple are all normal, reflecting different plant sources) surrounding the brood. A healthy colony will have a dense, varied pollen band. If you see only one or two colors, or the pollen ring is sparse or absent, the colony may be nutritionally limited, especially during periods of low floral diversity such as midsummer. Pale, watery-looking, foul-smelling pollen stores can sometimes indicate sacbrood virus, though that condition is more definitively identified by examining the larvae themselves.

ContextIf honey stores are below two frames and no significant nectar flow is currently underway, supplemental feeding is appropriate. A 1:1 sugar-to-water syrup (by weight) stimulates brood rearing and mimics a light nectar flow — use it in spring and early summer when you want to encourage colony expansion. A 2:1 syrup is thicker, closer to ripened nectar, and is used in fall to build winter stores without triggering excessive late-season brood. Pollen substitute patties, placed directly on the top bars of the brood box, supply protein when natural pollen is unavailable or insufficient. Log what you fed, how much, and when — this lets you track consumption rates and adjust quantity at the next visit rather than guessing.

ContextQueen cells fall into two categories with very different implications. Swarm cells hang from the bottoms of frames, often in clusters of several, and are built when the colony is preparing to reproduce naturally by splitting. If you find multiple swarm cells — especially capped ones — with the existing queen still present, a swarm may be hours to a few days away. Emergency queen cells are constructed rapidly on the face of a brood frame, typically over an existing young larva, when the colony has suddenly and unexpectedly lost its queen. A single rough-looking cell built mid-frame after you confirm queen absence is an emergency cell — the colony is self-correcting, which is a good sign. Never destroy all queen cells unless you have a confirmed alternative queen ready to introduce. Record the number, location on the frame, and developmental stage (open cup, egg present, capped) of every cell you find.

ContextCongestion is one of the primary triggers for swarm impulse. A colony with all frames fully occupied — brood at every stage, nectar curing in all available cells, little empty comb visible — has no room to expand and will prepare to swarm regardless of the beekeeper's intervention. The practical threshold is roughly 70–80% comb utilization in the upper box: at that point, add a drawn super above if the honey flow is active, or consider a split if the colony is strong and swarm cells have appeared. A split takes 3–4 frames of mixed brood, adhering bees, and resources into a new box and introduces either a purchased queen or relies on the bees raising one from the donated brood. Adding space too early does no harm; adding it after the swarm impulse has fully set in rarely reverses it.

ContextSmall hive beetles are compact (about 6mm), dark, fast-moving, and run directly from light when you lift a frame — watch the corners of the box and the undersides of frame lugs. Healthy, populous colonies manage beetle populations themselves by corralling them into propolis-daubed 'prisons' they cannot escape. A weak colony or one stressed by other factors can be overwhelmed. Beetle larvae are cream-colored, leggy grubs that leave slime trails through the comb and can cause it to ferment, which triggers absconding (the entire colony abandons the hive). In-hive oil traps — small plastic trays filled with vegetable oil that bees walk over but beetles fall into — are effective passive management. Count adults during your inspection: 5–10 in a strong colony is manageable; 30 or more indicates immediate action is needed.

ContextWax moths target weak, queenless, or understocked colonies and stored equipment. The larvae spin silken tunnels through comb, leaving gray webbing, frass (coarse droppings resembling sawdust or pellets), and destroyed comb. A strong colony evicts wax moth eggs before they can hatch. If you find active webbing, assess how much comb is affected and whether the colony's population is adequate to protect the remaining area. Remove frames with significant damage and freeze them — 24 to 48 hours at 0°F or below kills all life stages, including eggs. Never store drawn comb in an unsealed box or barn; wax moths will locate it and destroy it within a single season.

ContextNosema apis and Nosema ceranae are microsporidian gut parasites that impair digestion and dramatically shorten a bee's lifespan. Visual signs include brown, watery fecal streaking on the landing board, the front face of the hive, and on frames inside — particularly noticeable after long winter confinement when bees have been unable to take cleansing flights. Infected bees may walk in disoriented circles or crawl in front of the hive and fail to fly. Because these symptoms overlap with several other conditions including pesticide exposure and Varroa-related viral damage, a definitive diagnosis requires microscopic examination of crushed bee abdomens. If you suspect Nosema, collect 30–50 bees into a sealed bag and send them to your state apiarist's lab or a university extension apiculture program for testing before committing to treatment.

ContextDeformed Wing Virus (DWV) is transmitted to pupae by Varroa mites feeding during development. Bees emerge with shriveled, crumpled wings that cannot unfold, leaving them unable to fly. They crawl on the bottom board and are typically dragged to the entrance and discarded by healthy workers. Observing 2–3 DWV bees in a large colony is within a normal range; finding 10 or more per frame, or seeing a substantial crawling population at the entrance, is a strong signal that mite loads have been above threshold for several weeks and that the colony has already sustained irreversible viral damage to a portion of its workforce. DWV bees cannot be treated — the only response is bringing the mite population below threshold so that bees raised from this point forward are not parasitized during their vulnerable pupal stage. Record your DWV count alongside your mite wash percentage.

ContextBees build propolis seals and organize their cluster around the precise location of each frame. Reversing or rotating frames disrupts the brood nest thermal arrangement and can place young larvae or capped brood in incorrect temperature zones relative to the cluster. If you removed a frame to inspect it, track which direction it faced and return it to the exact slot it came from. When inspecting multiple hives in a single session, never carry a frame from one hive to another — even briefly — as this is one of the primary transmission routes for American Foulbrood spores and other pathogens between colonies.

ContextYour hive tool moves between frames and accumulates propolis, wax, and potentially pathogen-laden material. A butane torch run over the blade and hook for 10–15 seconds destroys most relevant pathogens including AFB endospores. Alternatively, carry a small spray bottle with a 10% bleach solution (1 part household bleach to 9 parts water) and wipe the tool thoroughly on a clean cloth between hives. This is most critical when moving between separate colonies or apiaries, but it is good practice even within a single hive session if you encounter any frame with suspicious disease indicators.

ContextYour inspection log is the single most valuable tool in your apiary over multiple seasons. Record at minimum: date, air temperature and weather conditions, queen status (seen / eggs only / cells present), estimated population in frames covered, mite wash result, stores estimate, any treatments applied, concerns flagged, and your plan for the next visit. Format matters less than consistency — a simple pocket notebook, a waterproof field notepad, or apps like Hive Tracks or Beetight all serve the purpose. A log spanning two or three seasons reveals your colony's seasonal rhythms, helps you anticipate swarm windows, tracks treatment efficacy over time, and can show a declining queen months before she fails completely. Inspect every 7–10 days during peak swarm season in spring, every 14–21 days in summer, and monthly in fall if weather and temperature permit.