Honeybees naturally swarm when the weather is nice, there is nectar and pollen available and their current hive gets crowded. Swarming is the way a honeybee colony reproduces. A swarm usually includes the queen and about half the worker bees from the existing colony. The existing colony raises a new queen and carries on while the swarm sets up housekeeping in a new place.
A swarm trap is not really a "trap". A swarm trap is a baited hive box that is made as attractive as possible for a swarm to move into. Since the bees can choose to move in (or not) and can choose to move back out (or not) some beekeepers prefer to call a swarm trap a "bait hive".
Honeybee swarms usually form a temporary loose clump (a bivouac) hanging from a branch, fence or post for a day or so. Scout bees from the bivouac search for a new home for the swarm to move into and that is what we want to provide with our baited trap.
Honeybee swarms move into all kinds of places. They have been found in upturned 5 gallon pails, water meter boxes, flower pots, cavities in buildings, etc. and (of course) natural hollows in trees.
Step 1: Supplies
For our simple bait hive we will need the following things:
A Sterilite black plastic waste basket* (Walmart ~$4)
A top* (scrap plywood or Coroplast political sign)
7' of cord or light rope (UHaul tie-down rope ~$3)
A 6" piece of an old branch cut in half for the porch
2 deck screws to hold on the porch
A wine cork
4 cotton swabs
A bottle of lemon grass oil (Walmart ~$6)
2 small pieces of old honeycomb (If you have some) or some small rotting wood chunks
A medium sized nail or 3" lag screw
A 2" piece of fat plastic straw
*See step 11 for the 3 size choices
Honeybees do not need a high-precision trap construction. Go ahead and change any part or location to suit what you have on hand.
Step 2: Tools
The tools you will need are:
A lighter (to cut rope or cord)
A marker (to mark where to drill holes)
A hammer (to pound nail in tree when hanging)
A drill with these four bits:
A tape measure
A utility knife
A Philips screw driver or bit for drill
Step 3: Prepare the Box
Drill three 1/2" holes three inches up from the bottom of the basket centered on the front. This is the entrance for the trap.
Drill two 1/8" holes in the bottom of the basket below the entrance. These are drain holes to allow any water that gets into the hive to drain out.
Drill a 13/16" hole about midway up one side of the trap. This is for the cork which will have a cotton swab with attractant on it.
Drill three 1/4" holes in the top edge of the trap as shown on the diagram. Two holes are at the back corners and one hole is centered above the entrance.
Screw the half-branch piece centered under the entrance using the two deck screws. This is the hive porch. The screws project into the basket and can hold two pieces of old comb.
Step 4: Prepare the Top
Prepare the wood top from a piece of 1/4" exterior plywood or a piece of Corplast (old political sign). Cut the top to 12" X 15" for the 5.5 gallon trap. (See step 11 for size options.) Any wood or light, hard, waterproof material will do, but thin plywood works nicely. It will keep the trap light in weight for easy handling.
Invert and center the trap onto the underside of the top and mark where the three 1/4" holes you drilled earlier are. (Two holes are at the back and one hole is centered at the front of the trap.)
Drill three 1/4" holes in the top where you have marked.
Paint the outside of the top if you want to. Leave the inside of the top unpainted so the bees can attach their new comb easily.
Step 5: Tie the Top on the Trap
Run the cord up through one of the corner holes in the trap, up through a corner hole in the top, over to the other corner hole in the top and down through the second corner hole in the trap.
Center the cord.
Tie a single overhand knot in the cord as close to the trap as you can.
This hinges the top on and makes a hanger for suspending the completed trap.
Use a pull-tie or piece of wire to secure the lid.
Step 6: Baiting the Trap
We will use two attractants to increase the chance of attracting a swarm into our trap.
If you have access to some old comb stick a couple of small chunks (about 2" X 2") on the two screws extending into the hive from the porch. This is not essential, but it helps the trap "smell" like a used hive. If you don't have any old comb then find some small rotting wood chunks and impale them on the two screw ends sticking into the hive. Honeybees like hollow trees for a home and we are trying to simulate that.
Lemon grass oil (LGO) is supposed to attract bees because it smells like a queen is inside. We will put a couple of drops of LGO on a cotton swab and rub it around the entrance opening. Another drop of LGO can be added at each end of the porch. Don't overdo it as a lot of LGO can be too much of a good thing.
Drill a 1/8" hole in one end of the wine cork and stick the LGO-moistened cotton swab into the hole. Slide the 2" piece of plastic straw over the swab. Push the cork into the 13/16" hole in the side of the trap so the swab is inside. Put couple of drops of LGO on the extra swabs and put them in a small plastic bag. Drop the OPEN bag into the trap and close the trap top.
Renew the LGO every couple of weeks to keep the trap smelling attractive.
Step 7: Locating the Trap
Locating your trap in a way that increases your chance of attracting a swarm is worth a bit of thought. None of the following suggestions is essential, but each adds to the chance of success.
It helps if the trap faces south-ish. That is anywhere from southeast to south to southwest is good.
It helps if the trap is 6-10 feet high. I usually just hammer the anchor nail in about as far up the tree or post as I can easily reach. Some people go up on step ladders to hang their hive but that seems overkill to me.
It helps to position the trap along an edge or a border. For example you could hang the trap along the edge of a woods or along a roadside fence. Edges seem to direct the scout bees toward the trap and help them find it.
It also helps to position the trap in a location where swarms have occurred before. You may not have seen swarms there before, but if you have then try there again.
Step 8: Hanging the Trap
Hanging the trap is simple. Pound a nail or lag screw into the support (tree, post, building, etc.)and loop the knot in the cord over the nail. The two tails of the cord can be used to tie around the tree or post to keep the trap in place.
The trap should tip forward and rest against the support at the bottom.
If you drove the nail in just above your head you should be able to hang the trap without a ladder.
You should also be able to reach the cork and renew the LGO on the swab every couple of weeks without needing a ladder.
Step 9: What to Watch For
The first sign of honeybee activity will be a few scout bees inspecting the trap.
The scout bees will go in and out of the trap and are measuring the size of the trap for suitability. The scout bees look for size, dark interiors, absence of cracks or gaps, good "smells" and other subtle bee-friendly factors.
Be alert for any bee activity around your trap! A few scout bees may be followed by the whole swarm.
If the trap passes muster then the whole swarm will arrive and flood in through the entrance. That is what you are hoping for. Success!
The bees will quickly start making comb on the inside of the top and begin hive-building.
Step 10: Then What?
OK. So a swarm has moved in!
The trap can serve as a honeybee hive for the remainder of the summer. A permanent hive will eventually be needed for a trapped swarm. The swarm trap does not have enough insulation for good wintering in cold weather.
Think about joining a local bee club so you can get mentoring and access to experienced beekeepers.
Step 11: Choosing Sizes
The Sterilite waste baskets (AKA trash cans) come in three sizes: 3 gallon, 5.5 gallon and 10 gallon. Any can can be used as long as the flat top makes contact all the way around the top edge of the can. Honeybees do not like gaps any place in the hive and if the top does not fit flush the scout bees will not like the trap.
I used the 5.5 gallon size for this Instructable as an example. The 3 gallon size might appeal to a gardener with more limited space and the 10 gallon size might be more appropriate where a larger field is available. Honeybee swarms come in many different sizes so it is just chance whether a larger trap or smaller trap will be preferred.
Here are the top dimensions I use and the specifications for each size of trap.
3 Gallon (11.4 L.): Sterilite Walmart # 550758928
Top: 9" X 13"
5.5 Gallon (21 L.): Sterilite Walmart # 567473328
Top: 10.5" X 16"
10 Gallon (38 L.): Sterilite Walmart # 552959941
Top: 13" X 21"