Ultimate Leprechaun Trap With Demonstration Video

How we got started.

My oldest son came home with a school project two years ago to build a Leprechaun trap. It was a creative expression exercise. He was supposed to create a plan, write a description of how to execute the plan and then build it (sounds like Instructables). In classic manner for our house we created the trap in the evening before it was due. We used a cardboard box, and some mousetrap parts. It was very basic but effective. That night we set the trap to see if it worked. Low and behold we were almost successful. Upon waking up the next morning he found that the trap had been sprung and there were a few strands of green fabric caught in the trap!! He was disappointed that we did not catch one, but he was beyond ecstatic that the theory was good and he so close to success. His enthusiasm had an interesting impact on his day at school too. When the time came to review the projects, his teacher explained the history of Leprechauns and their fictitious background. Of course he had to correct his teacher. But, he was brimming with confidence and also able to provide her with the demonstration of his built trap and showed the whole class proof with the fibers. She we very impressed and backed down. She let the class know that maybe he had made a meaningful discovery.

Needless to say that my younger son has been waiting two years to build his trap. He carefully planned his design (I gave him a few pointers to make it more effective). Then we built it. When I say we, I want to make sure you look closely at the pictures. He drilled every hole, screwed in every screw and did all finish work on this project. This is truly his Instructable. I was merely along as a consultant and assistant to his efforts. He is confident you will like his design and he is convinced we will be successful in catching a real Leprechaun this year. Please watch the video at the end.

Parents and Teachers, this is a great educational instructable. It allows you to teach all about critical thinking and problem solving. They get to create a theory of what method will work best. They get to work through the challenges of building from their design. The best part is they get to see if their design actually works when all said and done. Along the way the get to use a large variety of tools and supplies. In this one project they get an education in Art, Carpentry, Science, Physics, Cultures, Folklore, Recycling, Humor (Leprechauns make fun of you when you do not catch them), and Forensics.

Note: This is an "Extreme" Leprechaun trap because it has superior strength and lightning fast spring action. EXTREME measures needed to capture EXTREMELY sneaky and crafty Leprechauns.

Step 1: Come Up With a Plan

My son wanted to catch a leprechaun this year. He started with a similar design to his brother, which was basically a trap door box that was mouse trap activated. After some discussion, we decided to go with a more ancient animal trap style that was mouse trap activated ( He bought the traps with his own hard earned money a while back. They needed to be part of the design no matter what!!). I cannot find his original blueprint but this is a version we used during the build.

Step 2: Parts List and Prep

Parts List
  • One piece of scrap wood. We used a scrap of flooring from my bench build (see my instructables). You can use a piece that works for you. Probably about 4" to 6" wide and about 14" to 18" long. Cost: Free
  • One small box. You can use wood or cardboard. We used the latter. He used about 1/4 roll of packing tape to reinforce it (he is determined to catch a leprechaun!!). He also put a washer on the inside to reduce the likelihood of the screw pulling through. Cost: Free
  • One small hinge. He got a small hinge from my junk box. It is about 3" across and was from a car glove box. Cost: Free
  • One mouse trap. My son bought a 2 pack of mousetraps with his own money. He was a frugal shopper and found them in the discount bin at the hardware store. Cost: .99 (I am a cheapskate and I like seeing his frugal genes)
  • Misc. Hardware. He used a few small wood screws, one 1/4" machine screw with nut and fender washer, some tiny screw eyes and string scraps.
  • Small dowel: He used this to tie around inside the box. This was to prevent the top string from tearing out of the box. Cost: Free, from our craft supply.
  • Paint. He used two different green paints from our crafts bin. Note shamrock on the base. Cost: Free.
I was so excited for him to get started, I forgot to take pictures of our supply arrangement before we started.

Step 3: Assembly

Let's get to building
  • Cut and sand wood: In our case the piece we had was a good size so we left it: approximately 4" wide by about 19". My son did a light sanding of it so his paint job would stick well.
  • Prepare box: We used cardboard so it needed some significant reinforcing. He used some packing tape and put on a few layers. Leprechauns have a hard time getting through heavy tape. Make sure the bottom is very flat. We did want any possible means of escape. Remember they are crafty!!
  • Attach hinge to wood and box: First the the hinge was attached with a couple small flat head screws about #8 to the board. Then he attached the box with a 1/4" machine screw backed with a large washer and nut to hold it securely. Note: we picked a mildly stiff hinge so the box will stand on its own at any angle.
  • Attach mousetrap: The trap was attached using 4 small wood screws. Probably overkill but keeping with the theme of "WE ARE GOING TO CATCH THIS RASCAL".
  • Rigged trip cord: A strong cord was attached first to the top of the box. We tied a short length of dowel to the inside of the box to prevent the cord from pulling through. The cord was then tied to the drop hinge bale (not sure of the technical name for mousetrap parts) of the trap. Note: we pre-loaded the bale while making the final knots to make sure when the trap is closed the box is held firmly to the wood base.
  • Rigged trigger string: My son used a lighter string for the trigger since it needs to be very sensitive. The lacing of the trigger string started with a tiny screw eye mounted right next to the bait holder of the mousetrap. The string was tied to that screw eye and strung through the bait holder. Once through the bait holder it was laced through another tiny screw eye on the wood straight across from the bait holder. The string was pulled along the edge of the board to about the middle of the box where the last screw eye was installed. He finished the trigger with a shiny gold arcade token tied to the end.
  • Finally he tuned the operations and painted it. Making sure to include a nice shamrock in the middle of the wood.
What Did We Learn In This Build
  • My son learned about a lot of stuff during this project. Some of the ones that come to mind are:
  • How to work with wood, including sanding, painting, drilling and installing screws.
  • How to modify designs as needed to accommodate miscalculations in your design. Luckily the design only needed a few minor tweaks.
  • Financial planning for projects. He used his own money for the trap in this build, which was the only thing we needed to purchase to do the project.
  • He did research on Leprechauns and what they like to steal for the bait.
  • How to speak in public, he needed to give a live demonstration for his class.
  • He got some physics principles too.

Step 4: Video Demonstration

He thought the best way to show you how it worked was with a short video. Enjoy.
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    11 Discussions


    7 years ago on Introduction

    We're from Ireland, and lived in both Dublin and Limerick, and how we wish we'd had a trap as good as this to keep those pesky leprechauns away from all of our treasure! Truly excellent! Well done!

    No. As a matter of fact the little rascal came in one night last week, disassembled the top without triggering the mechanism and made off with the coin. To make matters worse he left a note taunting of his success!


    7 years ago on Introduction

    I like this assignment, and thanks for detailing your build. If their teacher is at all interested, we do give free pro accounts to teachers. (And any teacher who assigns something like this would likely be interested.)

    1 reply

    Excellent write-up of an excellent project. I always liked assignments like this. I realize that they are harder to grade than a standardized worksheet, but the students learn and stay enthusiastic about class. One of my son's best teachers had the class make 2-liter soda bottle rockets, combining physics, art, and fun.

    1 reply