Making Carpenter Bee Traps




Introduction: Making Carpenter Bee Traps

Carpenter bees are nature's answer to the cordless drill.  They are incredible drillers and cause significant damage to wooden buildings by burrowing long holes.  The bees do not actually eat the wood but drill tunnels as a place to lay eggs.  Their preference is to find an old hole and drill further into the wood each year before laying their eggs.  Over time, the continued removal of wood causes significant damage and eventual failure of the wooden support. In the forest, bees find old dead wood to drill into and cause no harm at all.  Unfortunately our homes and barns are a big target for carpenter bees with an unlimited amount of exposed dry wood for nesting.  Picture 2 shows damage in a piece of lumber and picture 3 shows how extensive the nests can be in a piece of firewood.

Carpenter bee traps are not an original idea, but in searching for an instructable, I discovered no one had posted plans.  Since I needed to make some traps I thought an instructable was in order.  There are many designs and you can google for images to see the variety.  Most of them are pretty close to this design.  

Step 1: The Trap Is Set

The trap is a simple wooden box with 1/2" holes drilled in all 4 sides at an upward angle.  Since the bees prefer to use an existing hole, these traps provide the hole they are seeking.  Once inside the box, the bees fly toward the light and end up in the plastic water bottle at the bottom.  Two things I saw mentioned online were that these bees like an overhanging roof and a sloped side to the box.  I included these design elements by providing an oversized roof and angling 2 sides of the box.

Step 2: Building the Box

You can use any wood you like for the box as long as it's unfinished and not pressure treated.  Carpenter bees don't like finished or pressure treated wood.  I happened to have some old barn wood that wasn't good for anything else and it made for some nice rustic boxes.  You need 5 pieces of wood to build the box.  The large sides are 7 1/4" wide at the top, 4 1/2" wide at the bottom and around 8" tall.  Mark 7 1/4" on one side of your board, set your miter to 10° and make the two cuts angled towards each other.  This will give you 4 1/2" at the bottom or pretty close.  These dimensions aren't set in stone so you can adjust to fit your fancy.  Repeat and you have your first 2 pieces.

The third and fourth pieces serve as the other sides.  They are made from 3" wide wood and it's easiest to just rip some 3" wide boards before you start.  I don't have the exact measurements for the length because it will depend on how tall you are making your box.  Instead, take one of the trapezoid pieces and use it to mark the length of the side pieces.  Your marks will be at angles oriented in the same direction.  These are also 10° cuts on your miter saw and make the top and bottom of the trap flat.  Assemble your box with some wood glue and nails.  Don't get your nails too close to the top if you plan to slope the roof (read on).

Picture 2 - To slope the roof a bit I tipped my miter saw 10°-15° and cut the top as far as possible.  I finished the cut with a hand saw.  When assembling your box make sure to keep the nails an 1" or so from the top so you don't saw them.

Picture 3 - Drill a 1/2" hole angled upward in each side near the top.  The bees prefer to climb up into a hole and it also makes it harder to find the hole when they want to leave.

Step 3: Making the Bottom of the Box

Inside the box is our 5th piece of wood which measures 3"x3".  Angled cuts (10°) are made on two opposite sides to accommodate the sloped walls of the trap.  Drill a hole in the center of the block which matches the size of the plastic bottle you are using.  I had a 2 1/4" hole saw and it fit my bottles pretty well although a bit small.  2 1/2" would probably be better but it's not critical as long as you can affix the bottle.

Once your hole is cut slide the bottle through, cut off the bottle and make some tabs with a sharp knife.   Staple the bottle tabs  to the wood and place the block inside the trap box.  Picture 5 shows what the inside of the trap looks like from the top.  When the bees enter the box, the plastic bottle is the obvious exit as it is the only source of light in the box.  The bees fly down and enter a second plastic bottle which we will prepare next. 

Step 4: Finishing the Bottles

To connect the "capture" bottle with the 1/2 bottle/funnel, tape 2 bottle caps together with electrical tape or gorilla tape.  Ideally it would be best to epoxy or superglue them together as that will last longer.  Once the caps are affixed together, drill another hole through the caps for the bee's escape.  Once you've screwed the 2 bottles together (pic 2) you are ready to put a roof on this old trap.

Update:  UncleSam created an instructable on how to connect the 2 caps using a 1/2" grommet.  Very nice permanent solution.

Step 5: Add the Roof and You're Done.

The trap needs a wooden roof with a couple inches of overhang and I used some old shingles.  You can simply use another piece of board as well.  Nail the roof to the top of the walls.  To hang the trap you can staple a string in the center of the top, add a hook eye if you used a board, or something similar.  I did something similar by drilling a hole in the shingles and passing a string out the bottle so I could tie a short dowel to it (pic 2).  Since the shingles aren't super strong, the dowel disperses some of the weight to a larger area of the roof.  

Step 6: Success!

Now hang your traps and catch some bees.  Supposedly the corners of your house/barn/porch are the best spot for these traps.  You may have to move them around a bit depending on your situation.  Hopefully your traps will look like this one after a few days!  Thanks for taking time to read about making bee traps.  If you have carpenter bees at your house, you know you need 'em!



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    133 Discussions

    "Carpenter bees don't like finished or pressure treated wood." You haven't seen them boring into my pressure-treated deck joists or my porch rafters, then! :-) I think they'll chew into just about anything.

    1 reply

    My pressure treatment pasture fence is about demolished in places.

    Before engaging in something so destructive to nature and the environment consider the benefits of bees. Why is it that man has to kill what they don't understand or care to understand. Try building nesting sites for these creatures before of killing them.

    17 replies

    Because these bees bore holes in the beams that hold up my deck, and the rafters supporting my porch roof. I value the structural integrity of my home.

    Carpenter bees aren't a huge source of pollination. Their numbers are too low for a given area to make much of a difference. If you want to encourage pollination, then start a hive of honey bees. Much larger concentration of bees and far less destructive than carpenter bees which equals much better pollination. Just ask the almond growers, they couldn't survive without plenty of beekeepers supplying them with bees for pollination.

    Honey bees aren't native will not pollinate some species of plants. Many of your food crops depend on solitary bees like the carpenter bees for pollination. Blueberries are probably the best example of this. Your response lacks understanding of a bigger picture.

    How sweet and cozzy! You don't have to watch them eating my log home! 1/2 inch holes are pretty big! They are smart too. They drill them up high so you can't get to them easily! As for the pollination bull, there are plenty of other creatures to do that, even the wind helps! So if a bug is doing some bad thing you would rather save it cause its "cute"? Get real!

    Thank you for your well thought out and intelligent reply. Obviously you have considered their benefits and feel that this species has no legitimate reason to keep around. Apparently you and your home in the country are a more important species to have on earth. Good luck with that.

    ljgtg. Ha, if you think a few of these will eliminate a species. That's funny.

    And yes, me and my home are more important. That's very kind of you to say.

    Those suckers are aggresive anyway. A pain to cut the grass around the shed and deck they have nested in, as anytime I get near either and the carpenter bees come at me. Whether or not they sting doesn't matter to me. I don't want to have bees attacking me when cutting my grass.

    ljhtg- carpenter bees are nowhere close to extinction, and trapping the ones that are near a house will not make them extinct. From your comment, it seems likely that you live in a city apartment that was built by someone else and is maintained by someone else. Your apartment required cutting trees and driving out woodland creatures just like everyone else's home did, and it requires continuing anti-pest measures to keep it standing and healthy.

    I never suggested the bees were nearing extinction and you would be 100% wrong about where I live. Please don't put words in my mouth or make false accusations.

    "pollination bull" eh?98% of what you eat requires those 'cute bugs'.Only corn and wheat are wind pollinated.So go ahead kill the bugs and enjoy living on bread and water in the future.

    AMEN! Providing nesting sites using various lengths of cane will entice the bees away from all manner of wooden posts,beams,boards.Lazy people kill.Smart people work with nature not against it.

    Not necessarily. I got a perfectly good dead tree in my yard the carpenter bees could nest in. Instead they "drill" holes in my deck and shed, causing structural damage to both. Sometimes you gotta take care of it by elimination.

    Had you or ljhtg gave this alternate suggestion at the start (preferably without the condescension), it would have been much more productive than the bickering that went on.

    That suggestion was my original comment, the bickering came after. Nor was it condescending but to each their own interpretation.

    I know this is an old subject. But it all depends on your location. If you are more out towards the country or you have land, then fine build a nesting area and be a savior of natures society....But, if you're like me and you live inside the city with a small yard, there is no place to create nesting grounds for these bees. These bees are highly destructive to the structures that humans live in. And, they are highly aggressive especially during mating time.

    As much as I would love to let them tear down my home and attack my family and neighbors(yeah right). They are a species of bee that needs to be dealt with, this trap is a ingenious idea, and I will bee making several of them ;).

    I can appreciate where you are coming from, indeed there are some species that cause a great deal of damage to structures. It may not work or be ideal for everyone, I only make the suggestion as an option that might. Good luck dealing with your situation.