As some people like to run around answering calls regarding swarms only to find that the majority are for bumble bees, wasps or the swarm has disappeared before they arrive. So I like to set bait hives and try to lure a swarm to me. It’s hit and miss and you have to treat it as fishing, sometimes you get something and others not so lucky, but what you do get are plenty of nibbles. It’s particularly interesting if you can position your bait hive close to where you can keep an eye on it to see if you have any scout bees checking it out. The excitement builds over a few days as you first see one, then two, six, ten and up to a couple of dozen scouts checking out your hive. You hope to see it go quiet and then anticipate the swarm arriving and does sometimes, but unfortunately not always. The beekeeper has inspected their hive and found it on the verge of swarming or someone has collected the swarm from the tree or god forbid the bees somehow have made a mistake and chosen something else over your hive.
So you have to set up your bait hive to make it as attractive to the bees as possible. It is considered the bees prefer a space of 40 Liters, this is an odd way of calculating a volume to me, but I guess covers all shapes and sizes. For us in the UK a standard national brood box is ideal and ideally an old one with the inside gone over with a blow torch.
Next is a solid floor with a small entrance say 2 cm square. A mesh floor may let light in and the bees don’t like that, you could block off the mesh floor, but also a simple solid floor is easy to make.
One old comb, but no stores what so ever as this will only encourage robbing and you will get all excited over nothing. The rest of the box is filled with foundationless frames and I think the bees prefer the foundationless frames over foundation.
Crown board with holes covered by a mesh of sorts leave any holes open and you may find your swarm, making comb in the roof cavity first, finally the roof.
Ideally you want the hive approx 2 m off the ground and facing south or at least in plenty of sun through the day. I have fitted them up trees, on garage rooves and my current one sitting on two brackets fixed to a wall. As this may involve a ladder or steps I screw my floor and crown board to the brood box so when getting the now heavier box down, full of bees there is no danger of the whole lot coming apart. I also remove the roof first and as by now you have sealed the bees into the hive the mesh over any feed hole comes into its own as ventilation, small but some nevertheless.
The final bit is to put a couple of drops of lemongrass oil onto a piece of foundation roll it up and slip it into the hive entrance as an extra attractant but the old brood box and old comb is perhaps enough.
I prefer to set up brood boxes with full compliment of frames and this way if a swarm moves in I don’t have to worry straight away in moving it and can give it plenty of time to settle, build comb and start to raise brood. Last year I picked up a cast swarm and left them in situ most of the season and they built up to a wonderful colony by the end of the season, although the hive was rather heavy by the time I came to move them off the roof.
One year I made a number of simple plywood boxes with the intention of sighting them in places that I would not visit that often and also it would be no great problem if someone decided to take them. One picked up a tiny cast swarm, but so small they never came to anything and why a cast could be that small was unusual, perhaps a tea cup of bees and could have been from an absconding mating nuc??
I recommend that if you have the space and spare kit you should give it ago as its great fun, especially if you can keep a close watch on the entrance. I have considered putting one on my boat this year, perhaps just a nuc box to see what happens.