If you keep bees, sooner or later they will swarm. This means that the queen and about half the bees in the colony will leave the Hive and try to find another home. Swarming is the natural way for the bees to propagate their race – after a swarm, instead of 1 colony of bees there will be 2, and if both survive, the overall bee population will increase.
So, in the interest of nature, should you not let the bees swarm? Well, no – for several reasons.
Firstly, mainly because of varroa mites, honey bees will not survive for long in the wild. Without treatment, varroa will eventually kill of the new colony – and this is obviously not in the best interests of bees as a species.
Also, if you are an urban beekeeper, it is obviously doubly important that you prevent swarms – a swarm of bees is not very welcome in a populated area, and if they set up home in the roofspace of someone’s house, they can cause real damage.
And of course, if your bees swarm it will seriously affect honey production – you lose about half of the bees, and the rest of the season is generally spent building up the numbers again, so you will be unlikely to get any surplus honey.
If your bees do swarm, they need to be collected (by you or by someone else) and put into a beehive of their own. Normally they will gather on a branch or gate post close to the hive, while scout bees go looking for a suitable new home. They will stay here for between 12 and 48 hours – this is your window of opportunity to collect them and put them into a new hive.
This is of course the positive side to swarming – that is provided you don’t lose them – you now have 2 colonies instead of one. Or if you are just starting beekeeping, getting someone elses swarm is a great way to get your first bees. And provided it is still early in the season, the new colony should be productive.
Remember the proverb – A swarm in May is worth a load of hay; a swarm in June is worth a silver spoon; but a swarm in July is not worth a fly!
Swarm Image courtesy bushfarms.com