Here’s some things our group has learned, from over 120 swarm collections over several years: what went right…. and what went wrong!
First though – what are swarms? – Within each hive is a queen who lays eggs which become new bees for that hive. But honeybee queens can’t set up a new colony on their own, they are too specialised. Swarms are how bees found new colonies – a queen flies off with 30-50% of the flying bees in a hive. Usually, they gather in a clump on, say, a tree branch, while scouts look for the best home available. While in this clump, we can easily gather them in a box and take them to a hive. Occasionally though, they fly straight from a hive to their chosen new home which could be a roof, chimney, hollow tree or if we’re lucky, an empty hive.
Swarms are useful because they can be used to populate empty hives, and act as a firebreak against disease – most bee pests attack the larvae, but only flying adults are in a swarm.
Early swarms are desirable because they have all year to build up and furthermore, a late swarm risks a dearth of food in this area (the June Gap) just as it is trying to set up home. The bees need to build up to a “critical mass” of numbers and stores to survive the next winter.
Unlike buying a nucleus (mini colony) of bees, or a package (an American abomination), swarms are free but take a year to build up to full strength – you don’t take honey in their first year. Prime swarms hit the ground running and build comb rapidly; afterswarms (casts) have unmated queens, are smaller, are later – so have less forage – and more likely to die in their first winter.
Some commercial beekeepers catch swarms, kill the queens and use the workers to reinforce honey-producing hives with queens they trust. Our group’s emphasis is to propagate survivor genetics and we particularly prize queens and swarms from unmanaged colonies.
Annual variations – swarm season here is approximately May to July, but it is different every year.
2019 has featured a mild spring with masses of flowers which are ideal conditions for bees, and swarms began around 12th April and have been plentiful.
2018 was the opposite, a false start to Spring tricked many colonies into using the lastof their stores to raise brood too early, and this was followed by an unusually long and severe deep freeze (“the Beast from the East”) which starved many colonies. There was also a drought for ~8 weeks in Summer limiting nectar supplies. For whatever reason, there were far fewer swarms in our region than usual that year. Very oddly, the later ones were larger – as if some colonies held on until they were full to bursting, then finally split to give one big prime swarm.
Also, in May 2018 we noted a remarkable number of swarms absconding after hiving. We weren’t sure why, but Will suggested it could be because so many colonies died, there were lots of good sites available. Another possibility is that swarms were overheating in hives due to an unseasonal heatwave. Normally in our climate, we’d only open mesh floors for added ventilation in high summer.
Lesson 1: Sometimes it’s best to walk away
One call in 2016 was to a swarm “20 feet up in a tree”. On getting there it was quite a lot higher… this is why you always need to ask a caller how highit is in terms like “is it within arms reach”. The caller lent me a really long ladder and I clambered up, but the bees were not just high up but a long way out from the trunk, there was nothing safe to lean the ladder against near them. I tried various things and eventually a neighbour lent me a pool cleaner, an extensible pole with a net on the end, which turned out to be an ideal tool – much longer and lighter than my own “bucket on a stick”. After some hours of repeated attempts, each more perilous than the last as the swarm moved up the tree, I got them, but reflecting later I realised this ladderwork had been reckless. There will always be anther swarm. This swarm absconded (see lesson 2).
Lesson 2: allow them to calm down before hiving them
It took a long time to get these bees, then it was an hour’s drive home over bumpy, winding roads and by the time I got home 4 hours had passed and the bees were pretty agitated. I forgot what I learned in previous years, to put them in the garage to cool down in the dark and hive them the next evening. I poured them straight into a hive, and they weren’t pleased. They absconded the next day and I never saw them again. Following this I made sure to let swarms calm down before hiving them, and I walked them in.
Lesson 3: Diffuse swarms are casts with virgin queen(s)
I went to a swarm on a low wall in a car park. It was noticeable that many were flying and I assumed it was about to fly off to a new home. I put an inviting dark box next to the cluster and was cheered to see some move immediately into it.
But once half were in, the rest didn’t follow. They continued flying. If they’d separated into two clusters I’d have assumed it was simply a cast with two virgin queens, but the others never settled. After over an hour of this I decided to go home and return in the evening – the bees would cluster for warmth as dark closed in. I labelled the box “bees – do not disturb”, added my phone number, warned neighbours, and went home.
Returning at dusk, I found the box where I’d left it and 99% of the bees inside. But the box was surrounded by rubbish – bottles, pens, stones etc. Asking some nearby 9 year old lads about this they said “yeah, we threw things at the box to get the bees to come out” (!!!)
I discussed this with their mother who came looking for them. The boys weren’t interested in facts like “that could have been very painful for you, and the bees”. On the other hand they were completely fearless, showed great curiosity and unlike anyone else they came right up to the box to examine it. I had to make them put on veils. They could make great beekeepers when older.
After hiving by Helen – which was just as shambolic as the collection – this swarm rapidly (1 week) dwindled to nothing. I now wonder if they had a queen at all. Next time I come across such a remarkably un-cohesive swarm I will not try to catch it.
I now watch swarms closely while catching them. If they act cohesively, as one mass they are probably prime. If they are difficult to box (bees keep flying, don’t settle quickly) they are probably casts with virgin queens, who don’t smell strongly enough for the workers to tell where she is. And if there are several clumps of bees, it’s probably a multi-queen cast. Multi-queen casts seem happy enough in one box.
Lesson 4: Some swarms are mad, bad and dangerous
Our group has collected 120+ swarms now and only a couple (1-2) were grumpy when hived, so we’ve always ignored the dogma spouted by some conventional beekeepers that swarms always give poor honey yield, are vicious, should be killed etc. I’ve noted that several people who assert this had a reputation for handling their own bees roughly.
It’s worth mentioning that most of the stings I’ve had from swarms have been through not wearing wellies, because bees falling to the ground try to crawl, not fly back up to the cluster. Your leg is a convenient “tree trunk” to crawl back up but if they get inside your trousers they become trapped, and eventually squashed, so they sting you. Lesson: always tuck trousers into wellies.
The one really vicious swarm our group collected, was from Kidlington (just north of Oxford), despite OBKA’s swarm officer warning us the swarms there were “mad” and to avoid them at all costs. It immediately began attacking anything nearby – people, other hives. In the morning there would be people passing nearby and they would be endangered. After a quick conference call with other beekeepers the view was unanimous – the colony would have to be killed, and killed immediately to save the good hive. (One uses a spray of soapy water, which can be washed out of the hive afterwards.)
In retrospect we think it is possible it was a starvation swarm, but whatever the reason its behaviour gave the beekeeper no choice. Since then another beek has collected a swarm from there which he said was good natured.
Lesson 5: but most are lovely
I was once collecting a swarm, after it had formed a clump on a bush; there were parents and kids nearby. They were a bit scared, so after checking my hand was not sweaty, I gently placed my hand in the swarm. No stings. (Because no stores or brood to defend!) People round me relaxed. Well, until the 5 year old boy decided to try bashing them with a stick, but that’s another story.
Lesson 6: Not all swarms will thrive
Good indicators: large. Cohesive (indicates mated queen, i.e. prime swarm). From a feral colony, or treatment free beekeeper. Don’t overbreed when hived. Build up a little surplus. Active.
Bad indicators: lethargic, breed too profusely and never build up stores, throw out all their babies (starving). Small swarms have more problems.
In the wild, perhaps two thirds of casts do not build up enough to survive their first winter. If hived, this drops to maybe one third – but still, some will still struggle and fail, even if supported, if only because the queen is unsuccessful at mating (perhaps because of a run of poor weather). You must learn from the failures and move on.
My own view now is to support small swarms / casts in their first year but let natural selection weed out the weak after that. If they did not build up enough stores to survive winter, even after an Autumn feed then they were unsuitable for this region.
The picture shows another tricky swarm, by the side of a lane near Carterton in 2019. During collection, cars passed and squashed many of the bees. The queen survived, but at last reports the colony was struggling with too few bees and symptoms indicative of poisoning from the road surface (tar etc).
One swarm we collected was killed by paint poisoning – the beekeeper had painted his hive with Dulux Weathershield and the fungicide in it killed the colony. Pollinators are small and sensitive, which is why farmers are advised never to spray crops in flower.
Lesson 7: Not all swarms will hive
Bees tend to abscond if you try to hive swarms immediately after driving them home (see lesson 2).
We have also found that swarms are more likely to abscond if you knock them roughly into the top of a hive and close the lid. The “walking in” method leads to almost no abscondings, we think it’s because the bees are choosing this home and completing their “swarm –> then cluster –> choose a home –> walk in” program.
Another factor seems to be that big swarms, in particular, are looking for one big uninterrupted cavity. You increase the chances that bees will stay in Warrés if you remove the bars from lower boxes when hiving, then add them back in once the bees have committed and built comb (say after 4-7 days).
It is possible to over-scent a hive when trying to make it smell attractive. Don’t use more than a couple of drops of lemongrass oil, if you use that as a bait, because too much will actively drive the bees out.
Recently 2 swarms have absconded from one apiary, and we suspect it’s because that apiary is next to a railway line with the associated low frequency vibration, which upsets many colonies.
(Conventional beekeepers might use a queen excluder to prevent the queen leaving and force the colony to stay.)
Lesson 8: Feeding swarms is a bad idea
When swarms leave their origin nest they gorge on honey and have fuel for about 3 days. If the original hive had a disease it can be carried with them. You want them to digest and destroy all pathogens.
To expand on this point: when they arrive at a new home they will build comb to store, among other things, any honey they make – or any surplus carried with them. If you feed them they do not need to use their internal food and will regurgitate and store it.
Swarms usually occur at times of peak nectar flow anyway – and I’ve noticed that they often ignore sugar syrup when a lot of nectar is available. They really don’t need feeding when lots of forage is around. They have evolved to use it.
Like all rules of thumb, there are exceptions. Sometimes you will pick up a swarm just as a period of heavy rain confines them to a hive, or maybe you are told when you pick up a swarm that they have been hanging on a tree for 3 days. In these cases yes, you do need to feed them, but try and ensure they’ve used up their internal stores first.
Lesson 9: Some swarms are tough
It’s not uncommon for swarms to settle in chimneys, and if someone rings about this we generally advise them to light a smoky fire to drive the bees out immediately, before they settle and begin building comb.
But one day in 2016 we got a call about a swarm which had come all the way down a chimney, and ended up inside someone’s living room. I think the queen must have accidentally gone too far down and the rest followed. It was like a scene from Alfred Hitchcock’s film The Birds. The colony clustered behind a curtain and the householder only went into the room mid-afternoon, by which time, sadly, many of the bees had died because the room had windows on 3 sides and was very hot in mid-July.
Collecting the swarm was straightforward, I put the queen in a box wedged near the cluster and they followed in. This left perhaps 1,000 – 2,000 bees in heaps under the windows (they flew towards the light) and in the carpet in front of the fireplace, which I left behind. Learn from my mistake: I learnt later that many of these bees could probably have been revived by spraying with water. Bees are pretty tough, you can revive motionless “frozen” bees under a hive on a cold day by holding them in your hand and warming them with your breath. Peter once gently revived an entire wet, cold swarm he found on the ground after rain with a hairdryer.
The bees were hived in a Warré and for two days they did little. I assumed they were dispirited from their trauma and would dwindle. Then, after 2 days they suddenly “switched on” and became very active. For the rest of the season they worked hard to establish.
Swarm personalities: This swarm showed an amazing Will To Live but despite feeding, was unable to reach critical mass after this, and died out over winter.
Personalities vary remarkably. I have had a couple of listless casts (probably not queen-right), one grumpy swarm, others which flew in adverse weather. Prime swarms tend to be very vigorous and focused. Eric has a colony called St Trinian’s which are quite excitable, but super-healthy, whilst their neighbours are sweet natured and average. Some colonies have hygienic traits and clean floors, some use propolis to reduce their entrances.
Lesson 10: Tanging doesn’t work
Tanging is the sound metal makes when it is hit and rings – a high pitched clanging sound. Tanging the bees is an old tradition which some say will make a swarm land, or move down a tree to a more convenient location. The Roman poet Virgil mentions the sound of cymbals will do this.
I tried it. It definitely does not work whatever rhythm you use. After further reading, I believe the purpose of tanging was slightly different – in the middle ages, if a swarm emerged from your hive you could follow it while tanging (bashing a pot with something). As long as the swarm was in sight you had the right to follow it anywhere and collect it when it landed – you were laying claim to that swarm. Also the noise served to warn others. Over the years the purpose of tanging has been forgotten and distorted.
Lesson 11: Go get the swarm immediately
Swarms can take up to 3 days to decide where to set up home… but sometimes much faster. I got to one address just 1 hour after a swarm settled there and it was already gone. The other day I got to a swarm within 10 minutes of it emerging and saw it disappearing into a chimney. In swarm season you need your full kit in the car and ready to go. Don’t bother finishing your lunch, just go!
Musings on catching swarms
OBKA’s apiary manager, Kevin, suspects that swarms don’t follow queens but the other way round. 3 times he’s seen queens join clusters of workers. He thinks that the clusters signal the queens “over here!” by a characteristic loud buzz as they settle.
On hearing this, Gareth commented:
“From my observations of getting swarms to settle directly into (or on) a skep (which I am often holding at the time), typically, a few bees will settle and sent (or maybe sound?) and the rest gradually follow. Although one rarely sees the queen settle, there comes a time when the aerial bees start to show considerably increased interest in the growing cluster and I guess this occurs when the queen has settled and they can smell her there. With casts, the queens (there are often several) can be quite late to the party and the nascent cluster sometimes takes to the wing again to move to a different spot, or the cluster fractionates into several groups around different queens. One wonders if the first bees to settle are part of the scout/pioneer group who look for new nest sites or whether they are nurse bees who are closer in relationship to the queen due to their feeding role? I watched a prime swarm recently which failed to settle before returning to hive. I suspect they had not managed to persuade the queen to exit the hive. They swarmed successfully a couple of days later.
“Prime swarms will sometimes cluster inside the hive for a day or two before emerging, especially if the weather is iffy. Maybe that is when the ‘where to go’ discussions take place. The pioneer bees rarely seem to number more than 100 -150 out of the total swarm bees of maybe 10 – 15,000. If one is ‘taking’ a swarm and wants it to stay put, these are the bees that one needs to persuade, or remove from the discussions. The latter can be done by collecting the swarm promptly from its resting place and hiving it before the destination discussions get going. In other words the opposite of what is generally recommended of leaving the swarm in situ (in the skep) until evening.”
For an unusual swarm story: see Jack’s experience of 2 swarms moving into the same hive!
Appendix: impress your friends with obscure nomenclature for swarms!
These days we talk of primes and casts, but some old books list further terms (the lists are regional, and not consistent). Here’s one –
- 2nd – Cast
- 3rd – Smart
- 4th – Squib
- Swarm from a swarm = maiden or virgin swarm