The World’s Geekiest Leprechaun Traps (GeekDad Wayback Machine)

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Maybe it’s a California thing, but it seems like most schools around here are doing Leprechaun Trap projects at the Kindergarten and First Grade level. The idea is this: each kid builds a trap and leaves it at school the day before Saint Patrick’s day. On the morning of Saint Patrick’s day the kids come in and all the traps have been “sprung” but the Leprechaun has escaped, leaving behind only some chocolate coins, some “gold” (colored stones) and some green glitter. It’s good fun for the kids and they get to, perhaps, learn a little science or mechanical engineering along the way.

So here’s our unscientific survey of the best Leprechaun traps out there!


Irja wins major geek points for incorporating a slinky into the trap she made with her son Gabriel. I’m not sure what the slinky actually does. I think perhaps it vacuums the Leprechaun up into the shoe?

Adam made a low-tech trap with his son Ben, but he has the best youtube video showing it off. Bonus points for using batteries as weights.


Steve Spangler has a great science blog, making him a true GeekDad, and talks about his PVC-based trap there. Also don’t miss a great green-water trick where he made all the water faucets in the house dispense green water using fizzy tablets.


Kevin incorporated slime and a radiometer into his trap, and his budget ballooned to over $100 as the project grew and grew. What good GeekDad project *doesn’t* go over budget?

Finally, we end with a truly geeky trap solution from 2nd-grade students Caffrey Fielding and Abby Kelly using Lego Mindstorms NXT, behold the power of Lego!

I found surprisingly few Leprechaun Traps out there that incorporate technology. If you’ve got your own geeky leprechaun trap project that you’ve done with the kids, link it in the comments.

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