Category Archives: Floors

Bring out your dead

It’s midwinter. There’s very little to do in the apiary. Time is probably better spent planning and preparing for the coming season (and drinking tea in the warm).

However, there are a few jobs that shouldn’t be forgotten.

Let the undertakers do their work

The first job is to ensure that the hive entrances are clear. This allows bees to readily exit and re-enter the hive for ‘cleansing’ flights during warmer days. During these days the bees will also remove some of the many corpses that accumulate during the winter. If the hive entrance is clear these can be removed easily. If the entrance is blocked they continue to build up and – on warm days – you can hear a panicky roar of trapped bees from inside the hive.

Corpses at hive entrance ...

Corpses at hive entrance …

Don’t worry about the loss of these bees. It’s what happens. The colony goes into the autumn with perhaps 30,000 adult workers. Four months later, at the end of December, there may be only about one third of this number remaining. Brood rearing is limited during this period (and at times non-existent), but picks up in early January.

Attrition rate

Even assuming no brood rearing, this means that 150-200 bees a day are expiring. If they are rearing brood, even at a significantly diminished rate, it means that more than 200 bees a day are dying.

For comparison, 300 bees is about a ‘cupful’ … the number you’d do a Varroa count on. Imagine dropping a cupful of dead bees on the hive floor every day for a fortnight. Unless these corpses are cleared away the hive entrance gets blocked. This is what the ‘undertakers’ clear.

On calm warm days you can find the corpses littered on the hive roof, or in front of the entrance, dropped there by workers carrying them away from the hive.

Since ‘flying’ days may be infrequent at this time of year and/or bees have other jobs to do, like go on cleansing flights or collect water, they may not carry the corpses very far … don’t be alarmed by the numbers of corpses around the hive entrance.

Don't count the corpses ...

Don’t count the corpses …

A bent piece of wire to the rescue

I mainly use kewl floors with a dogleg entrance slot (see the top image on this page) that reduces robbing by wasps and negates the need for a mouse guard. I’ve fashioned a simple piece of bent wire to keep the entrance slot clear of corpses on my irregular visits to the apiary during this time of the year.

Kewl floor unblocker ...

Kewl floor unblocker …

I’ve only ever had problems with large, double-brood colonies after very extensive cold periods (~4 weeks with hard frosts every night) when the entrance has got blocked. One colony I managed to save despite it showing signs of Nosema after the bees were trapped for several days.

It takes just seconds to check that the entrance is clear and gives considerable peace of mind. If you use mouseguards it’s worth checking the holes aren’t all blocked after an extended cold period.

Next week I’ll discuss the other important winter check … are there enough stores remaining to stop the colony starving?


Colophon

Anyone familiar with Monty Python will recognise the post title.

This was one of the well-known scenes from Monty Python and the Holy Grail, a 1975 film parody about the Arthurian legend and a low-budget quest for the Holy Grail. The film usually ranks close to the top in surveys of the best comedies of all time, with another Monty Python film (The Life of Brian) often topping the tables.

In the film there’s a further scene (A self-perpetuating autocracy) which involves a political argument with interesting parallels between the public perception 1 of a colony of bees and the biological reality. This is topical, with the recent Deloitte report on women in leadership roles holding back the careers of other women they perceive as a threat.

Perhaps a topic for a future article … ?

Queen bees and the self-perpetuating autocracy.

 

Landing boards

I’ve bought and used a number of Abelo poly hives this season. I’m going to review these once I see how the colonies perform overwinter. However, one of their ‘features’ is an integral landing board that forms part of the removable floor (colonies 1 and 3, facing, below).

Abelo poly National hives ...

Abelo poly National hives …

Landing boards are great. They provide a large flattish or gently sloping ramp that leads to the hive entrance. There’s something mesmerising about watching heavily-laden foragers performing an inelegant ‘tail-down’ crash-landing several inches short of the entrance, righting themselves, and marching purposefully forwards into the gloom of the hive.

During a heavy nectar flow this happens dozens of times a minute, with a strong colony making about 35,000 foraging trips per day. It’s great to rest your elbows on the hive roof, peer over the top and watch hundreds of foragers bringing the nectar back, 40 milligrams at a time.

Integral landing boards and DIY

Mine's bigger than yours

Mine’s bigger than yours

Landing boards must be popular with other beekeepers as well as they regularly feature in commercially available hives. The Abelo implementation is relatively neat, projecting perhaps 5cm from the front face of the hive.

Other variants are rather more in-your-face. The version in the image on the right is on an early variant of a Maisemore’s poly National hive (I think – please correct me if I’m wrong – Matt Harris helpfully corrected me here … they’re Paynes hives). Frankly, I think it looks pretty ghastly, but at least returning foragers could crash-land some distance away and still walk the last few hundred yards unimpeded 😉

If your hives are cedar you can easily add a flat or sloping landing board to the front of the floor. If you’re going to do this use reasonable quality wood – the exposed edge of a strip of plywood tends to delaminate pretty quickly. Alternatively, build something cheap, functional and easily replaceable from Correx.

Thorne's budget hive ...

Thorne’s budget hive …

The bee shed houses up to 6 colonies, each with a simple short ‘tunnel’ ending in a 1-2″ aperture in the vertical shed wall. I’ve built simple Correx landing boards on these and they’ve performed extremely well over the last two years. Each piece of folded Correx is a distinctive colour to aid the bees returning to the correct hive.

Landing boards ...

Landing boards …

If you take advantage of abandoned ‘For Sale’ signs you can get Correx in a wide range of contrasting colours which saves having to spray paint them before use.

Take a stand

Landing boards don’t need to be attached to the hive front or floor. Some of our early research colonies were housed in lovely cedar hives built by Pete Little of Exmoor Bees & Hives. He provided stands with integral sloping landing (‘alighting’) boards. These are great, though they extend the need for compatibility from the hive itself to the stand as well.

Stand and integral landing board

Stand and integral landing board …

Nice, but not needed

Despite the pleasure to be gained from watching bees return to the hive entrance, landing boards aren’t really necessary and they can get in the way.

Feral colonies generally don’t have the benefit (or need) of a nicely sloping landing board. They cope admirably with a simple unadorned hole through the soffit, with nothing more than the painted boards to cling to … upside down. Crevices or holes in trees, or the church tower, probably have ‘grippy’ surfaces that aid arrival, but there’s no evidence they’re selected on any criteria other than the volume and overall location of the potential new ‘home’.

I used to build my preferred floor – the kewl floor with a mouse-proof and wasp-resistant ‘L’ shaped underfloor entrance – with a shallow integral Correx or plywood landing boards.

Original design

However, over time these all got damaged in transit, or I got sick of bees wandering underneath the floor if they landed on the stand, not the landing board. I’ve recently described a modified entrance to these kewl floors, again made from Correx, that is a marked improvement.

Correx landing board ...

Correx landing board …

There’s a very short video on the page describing these modified entrances showing bees landing and entering the hive perfectly well.

Damaged in transit … or in a pile (up)

The main problem with any sort of protruding landing board is that, by definition, it protrudes.

It therefore gets in the way.

It makes strapping hives up during transport more difficult and means the hives don’t stack together quite as neatly. I only move small number of colonies about, so it’s the inconvenience, not the space, that is the issue.

Abelo hives in transit ...

Abelo hives in transit …

Similarly, during the winter or after uniting colonies in the season, spare floors and other pieces of kit need to be neatly stacked out of the way. Protruding landing boards prevents them being placed on the top of the stack (because the roof fouls the landing board) and – in certain orientations – stops stacks being pushed close together.

Stacked boxes

Stacked boxes …

As an aside, you probably don’t want these floors at the bottom of the stack. Firstly, you’ll inevitably need one when putting together a new hive and it’s easiest not to have to remove the entire stack to access the floor. Secondly, unless blocked off with a sheet of polythene or Correx, they’ll allow wasps and bees access to the stack … or even encourage a swarm to move in.

So … over the years landing boards on my hives have evolved or, more accurately, atrophied. They’re now only present on the outside of the bee shed, on purchased poly hives and, in a rather truncated version, at the cavernous mouth of the Thorne’s Everynucs that I favour.

No landing boards here ...

No landing boards here …

Completely floored

It’s still too cold to undertake a full hive inspection (it might not be with you as I discussed last week) but one task that should take place in early Spring – whatever the weather – is cleaning the hive floor.

Knee-deep in corpses

Bees knees anyway.

During the winter the colony is much less active. Low temperatures mean there are few opportunities for workers to drag out and dispose of the corpses of their half-sisters. Consequently, depending upon the attrition rate (which in turn is at least partly dependent on the level of virulent strains of DWV in the colony), a layer of dead and increasingly foosty bees can build up on the hive floor.

Winter debris ...

Winter debris …

On open mesh floors this usually isn’t a major problem. On solid floors, particularly when there’s a bit of damp as well, it can get pretty unsanitary. Whatever the floor type, in due course the bees will clear the floor once the season has warmed sufficiently. However, cleaning and replacing the floor is a 30 second task that causes very little disruption and gives the colony a hygienic start to the season.

(Almost) smokefree zones

Place a cleaned floor adjacent to the colony. Gently insert the flat of the hive tool between the floor and the bottom of the brood box and make sure they’re separate. Often this joint isn’t heavily propolised (in comparison to the crownboard) and is easy to split. Lift the brood box and gently place it onto the adjacent clean floor, remove the old floor and slide the colony back into the original position. The entire process takes longer to read than to complete.

You can replace the floor without smoking the colony, particularly on a cool day with little hive activity. However, a very gentle waft of smoke across the entrance will push the bees up and out of the way. If you’re quick, gentle and use a tiny puff of smoke it’s possible to swap the old floor out without a single bee coming out to investigate things.

A clean start

The removed floor needs to be cleaned. Scrape away the corpses with the hive tool. Assuming the floor is wooden, with or without mesh, it can then be scorched with a blowtorch before being pressed back into service. If the floor is poly the blowtorch is not advisable 😉 After scraping off the lumpy debris it needs to be scrubbed thoroughly with a strong washing soda solution.

Scorching ...

Scorching …

In a busy apiary it’s possible to spend a happy hour or so removing, scraping, scorching and replacing in a cycle, meaning that you only need one additional floor than the number of hives.

 

Avoiding disaster

Top view of Kewl floor

Top view of Kewl floor

Kewl floors (sometimes called Dartington-inspired floors) have an ‘L’ shaped entrance that I think offers advantages to the colony when defending against wasps (or robbing by nearby colonies) and negates the need for mouse guards. However, the very feature that provides these advantages – the ‘L’ shaped gap about 9mm high – also makes them liable to get blocked with bee corpses during late winter.

During the depths of the winter, with a relatively quiescent colony and winter bees that are only a couple of months old, this isn’t usually a problem. However, as the winter turns to spring and the colony starts to become active again the attrition rate increases. As the weather improves and the winter bees expire the corpses can block the entrance, trapping the remaining colony inside.

Blocked Kewl floor

Blocked Kewl floor …

This is the sort of thing that should only happen once. Early in the season you go and visit the apiary on an unseasonably warm and calm day. With one exception the colonies look reasonably active. Foragers are returning with pollen and there are bees setting off on orientation flights.

If you listen carefully at the hive with no activity you might be able to hear the bees panicking inside. Splitting the brood box from the floor reveals the scale of the devastation. It’s a distressing sight. If you’re lucky there will be good numbers of flying bees. If you’re unlucky the colony will have already perished or there will be obvious signs of Nosema.

Kewl floor unblocker ...

Kewl floor unblocker …

With reasonably regular visits to the apiary this is a situation that can easily be avoided. Insert a piece of bent wire – I use an old bicycle spoke – in the entrance slot, turn through 90° and drag it across the full width of the entrance. The ‘vertical’ piece of the wire needs to be longer than the depth of the entrance slot on the floor, but not so long that it fouls the bottom of the frames.


 But, do we always learn from our mistakes? I’ve had this happen a couple of times. In both cases the colony was strong going into the winter and on a double brood box. The first time the colony perished, though it’s not actually clear whether they died from being trapped or from a midwinter virus overload. The second time, April 2015 (shown in the hive photo above), the colony survived. When I discovered the blocked entrance there were still lots of flying bees. I swept the floor clean and cleared the entrance, reassembled the hive and left them to it. On checking a couple of days later they were taking in pollen and I found the laying queen, none the worse for wear, at the first full inspection the following week.

 

 

Even kewler floors

So-called kewl floors have underfloor entrances that are pretty-much rodent proof (so you don’t need mouseguards in winter) and are easy to seal when needed for transporting hives or administering vaporised oxalic acid. They are very easy and inexpensive to build. The last batch I built were all fitted with a Correx landing board that protruded a centimetre or so. It turned out that the ‘design’ (a rather grand word for the bodged solution I came up with at the time) was not ideal so I’m gradually replacing them with a modified version that corrects the worst of the faults of the original.

New Correx landing board ...

New Correx landing board …

The problem

  1. The protruding landing board inevitably got a bit bashed about when transporting colonies
  2. The gap underneath the landing board disorientated bees who climbed up the hive stand or otherwise undershot. This was particularly noticeable when reversing colonies during vertical splits. I’d previously fitted a plastic ‘skirt’ to some hives to fix this (see pic below).
  3. The ‘edge’ of the Correx provided a narrow and slippery target for heavily-laded foragers returning to the colony. Many lost their grip and fell off into the grass before having a second or third attempt at entering the hive.

The solution

An L-shaped piece of Correx (of course), though this time not protruding, with a rough textured integral ‘skirt’ to block the gap below the hive entrance works well. To make an acute bend in Correx you need to make two parallel cuts through one skin and remove the intervening ‘rib’. This takes longer to write than to do. After stapling the Correx in place I spray paint it and sprinkle sand onto the wet paint. You can use different colours to help orientate bees and minimise drifting. Alternatively, use multi-coloured ‘repurposed’ estate agent signs and a clear spray varnish of some type.

Other improvements?

The final change I’d intended to make to these floors was to add a second entrance on the opposing side. Some hive manipulations involve turning the colony 180° on the stand – these include vertical splits and using a Cloake board for queen rearing. Rather than manhandling the entire colony it would be much easier to seal off the front of the hive and open a hinged entrance at the rear (much like opening and closing the gates on a Snelgrove board). Unfortunately, this batch of floors were over-engineered, with the upper upper rim glued and screwed in place, so this modification will have to be introduced when (or if) I next build floors.

New landing board in action …


The original landing board was held in place with gimp pins. Inevitably these had rusted which made removing them a bit of a pain. When replacing them I used stainless steel staples (like these from Arrow) with the hope that this will make future removal of the landing board easier.

 

Winter checks for kewl floors

Kewl floor

Kewl floor …

The majority of my full colonies are on kewl floors. Some call these ‘floors with underfloor entrances‘, which is a bit more of a mouthful. These floors have narrow ‘L’ shaped entrances; the bees are forced to access the brood box through a 8-9mm high or wide slot, negotiating a 90º bend en route. For the majority of the season these offer more than enough advantages to easily outweigh their slightly more difficult construction (though you can buy something broadly similar if needed). These advantages include:

  • integral (and readily replaceable) Correx landing board
  • no need for mouseguards – even determined mice can’t negotiate an 8mm right angle
  • guard bees can occupy both the landing board and brood box entrance so far fewer problems with robbing or wasps (and if these are really a problem a simple 9mm lathe can be pushed into the entrance leaving a single bee gap at one end)
  • easy to seal for transport

Other users of these floors also claim the absence of draughts is a benefit but, since they also have open mesh floors, I don’t think this is likely to make much of a difference.

I’m only aware of three disadvantages of this type of floor.

  • they are not suited to the Varrox-type OA vaporisers i.e. the passive heating pan that is designed to be pushed through the hive entrance. This is not an issue if you use a Sublimox-type ‘active’ vaporiser I’ve described previously
  • bees can be confounded by the gap under the landing board when reorientating to these floors, though there are quick’n’dirty fixes to this and it’s only ever an issue for a few days. For the same reason, clipped queens might – on returning to the hive – miss the entrance and end up underneath the floor (though this happens with floors and normal entrances)
  • during long cold winters the entrance can become blocked with bee corpses – the only really significant problem and easily avoided

Bring out your dead

Blocked Kewl floor

Blocked Kewl floor …

There can be a high loss of bees from the colony during long cold winters. This is generally not an issue during the depths of winter, but as the weather warms slightly and the colony becomes more active – and, inevitably, the overwintering bees get older – the attrition rate rises. If the weather still isn’t warm enough for the corpses to be removed they can end up blocking the entrance. Twice in recent years I’ve had colonies trapped inside. In both cases these went into the winter as strong double-brood colonies and – due to work commitments – weren’t checked for 4-6 weeks in late January-early March. In both cases I managed to save the colonies, but they were severely stressed by the situation, with signs of Nosema, and needed mollycoddling for several weeks at the start of the season proper.

Fortunately there’s an easy solution. On your weekly apiary winter checks (or however frequent they are) push a bent piece of wire into the entrance, turn it to project up through the vertical part of the entrance slot and slide it along the full width of the hive to ensure the entrance is clear. Any old piece of wire should be suitable as long as it it short enough not to foul the bottom of the frames. For a few years I used an easily-lost piece of wire coat hanger. More recently I added a handle to a stainless steel bicycle spoke … with a little hook so it can hung up in a “safe place” (which, of course, is no guarantee whatsoever that it won’t be lost 🙁 ).

Kewl floor unblocker ...

Kewl floor unblocker …

Floor change

Old floors …

Old floors …

At the beginning of the season it’s a good idea to move colonies onto a fresh, clean floor, removing the old one for cleaning and sterilising. Having built a number of new Kewl floors this winter I made did the floor change a fortnight or so ago. A couple of colonies had clear evidence of a chalk brood problem which should be rectified by requeening later in the season. The new Kewl floors have a Correx landing board with a large gap separating it from the hive stand. Colonies that had previously had floors with other types of entrance, particularly where the bees had landed on the stand and walked up and in, experienced some confusion with the new raised entrance. To avoid the bees clustering under the floor I pinned a strip of DPM (damp proof membrane – used to wrap the hives up in winter to avoid woodpecker damage) across the front and so encouraged them to choose the correct route home.

Kewl floor - fixed ...

Kewl floor – fixed …

Kewl floors

Kewl floor

Kewl floor

Floors can be as simple as a sheet of ply with three lengths of softwood to raise the brood box up slightly. However, open mesh floors are increasingly preferred, providing good air circulation and easy Varroa monitoring. Inevitably the design of the floor also influences the entrance to the hive. Dartington-type hives incorporate an underfloor entrance that offers several advantages. They negate the need for mouse guards in the winter and provide additional protection against wasp attack. I’ve used this type of entrance on floors of National hives for a few years having read a description of them online by Graham White of Edinburgh beekeepers. The style I now use is slightly improved (or at least altered) and is inexpensive and easy to construct.

Note … I’ve recently discovered that these floors and entrances have been referred to as Kewl, for reasons that are not entirely clear, in posts on the BKF by Hombre and others. This is certainly less of a mouthful than ‘Dartington-inspired’.

The key feature is the L shaped entrance. Bees land or enter via a narrow, horizontal aperture, walk to the back wall of the entrance and then climb vertically to enter the hive somewhere in the region of the second or third frame (warm way). The vertical part of the entrance is no more than 8-9mm wide. My preferred floors also have the horizontal aperture only 8-9mm high. I also like landing boards despite the fact they make hives more difficult to transport. I’m slowly converting the landing boards on these Kewl floors to Correx … they are easy to replace, totally weatherproof and come in a range of colours.

No mouse guard is needed because a mouse cannot squeeze through the tight angle in the L-shaped entrance. In addition, bees are able to defend the entrance against wasps both at the external opening and at the point at which the entrance joins the brood box. However, if wasps are really troublesome,  you might still need to reduce the entrance to a single bee space and this is easily achieved by simply blocking most of the external aperture with a piece of 8-9mm softwood.

Construction

Construction is simple. Two side rails of pressure-treated wood, cross pieces from readily-available softwood, some scraps from the offcuts box, a piece of Correx and a suitably sized piece of mesh. The following list of parts is for a National hive (planed softwood unless specified) :-

  • 2 x 46cm long 38mm x 63mm pressure-treated decking wood (B+Q)
  • 2 x 46cm long 46mm x 21mm
  • 1 x 46cm long 21mm x 21mm
  • ~1m of 21mm x 9mm
  • ~2m of 21mm x 21mm
  • Correx sheet 10cm x 45cm
  • A few 40mm x 4mm screws, four 50mm x 4mm screws, a few gimp (frame) pins, exterior wood glue, a bee friendly preservative, a drill and bits, tenon saw, small hammer, knife,  screwdriver, Elastoplast (just in case)

Remember, with woodworking for beekeeping, propolis is your friend.  Build flat and square and the bees will fill in any imperfections in the joints!

  1. Join one piece of 46mm  x 21mm and one of 21mm x 21mm (both 46cm long) with two short pieces of 21mm x 9mm, each 60mm long. Glue and screw as appropriate. This forms the vertical part of the entrance (shown second from the right in Fig. 1).
  2. The pressure treated decking wood forms the side rails of the floor. This is the only part of the floor in contact with the hive stand/floor. Cut a 76mm x 21mm section from one end of each piece and a 46mm x 21mm section from the other end. These respectively form the front and rear attachment points for the cross pieces and are also shown in Fig. 1.
  3. Using a flat, square and true template (such as a 46cm square piece of ply; Fig. 2) glue and screw the cross pieces to the side rails. Clamp everything down and leave it all to dry.
  4. Turn the floor upside-down. Add 21mm x 9mm spacers to the underside of the entrance cross piece (see Fig. 3) using gimp pins only. The landing board will be attached to these spacers in due course. Only fix them in place with gimp pins so you can replace them should the wood rot … they are exposed to water if rain is driven in through the entrance.
  5. While the floor is inverted add two short (16mm) screws equally spaced as ‘stops’ to prevent an entrance block being pushed back too far.
  6. Turn the floor the right way up again and add a strip of 21mm x 21mm all around the edge, glued and screwed down (see Figs. 4-8). The brood box will stand on these. The easiest way to do this is to cut them a few millimetres too long (say 45cm or so) then cut them down to length after fixing them in place (I never suggested this was going to be ‘proper’ woodwork!).
  7. Give the entire thing a couple of coats of bee-safe preservative such as Ronseal Fence Life (Fig. 9). Once it has dried cut the Correx landing board to size and fix it in place using gimp pins (Fig. 10 & 11). I usually have the landing board can protrude from the front by a couple of centimetres. However, if you move your hives a lot it can get in the way (and prevents them being packed together in the trailer) and so can be simply flush with the front of the floor. If it does get damaged it can easily be replaced.
  8. Cut a piece of mesh to fit and fit it in place with roofing nails. Remember to leave the upper entrance to the L-shaped entrance slot clear!

You can create an entrance block from an offcut of 21mm x 9mm softwood, about 1cm narrower than the width of the entrance slot. When in place this provides a narrow entrance on one or other side of the hive front (Fig. 12). To allow the use of a Varroa monitoring board add horizontal runners on either side of the side rails.  Make the board out of Correx.

When you first switch over to this type of floor bees may cluster under the entrance, particularly if they’ve been used to landing on the hive stand and then walking up … help them by packing the space under the landing board with grass for a few days (or use this quick fix).  They soon learn.

Check the entrance remains clear in the winter …

The only problem I’ve encountered using this type of floor is that, rarely, the entrance gets blocked with corpses during a long, cold winter. The best way to prevent this is to periodically clear the entrance using a bent piece of wire – a cut down coat hanger is ideal. If you do this on your fortnightly checks things should be fine.

A version of this article first appeared in Dr. Bodgit’s DIY column in Bee Talk, the monthly newsletter from Warwick and Leamington Beekeepers.