Growing up, my family didn’t do much for Halloween, but as my kids have grown up, it has become one of my favorite holidays.
Part of this is because of how much enjoyment my kids get out of the slightly sinister side of Halloween. My kids love the morbid side of Halloween, particularly my preschooler. Her favorite Hallooween activtities have been the ones that feature blood, zombies, ghosts, and other creepy things. This year, our Halloween STEM activities have been pretty creepy, and my kids have never been happier.
Our latest project is the voodoo doll leakproof bag experiment.
This slightly violent Halloween activity mixes science with spooky in the best way possible.
Don’t miss the complete list of Halloween science experiments!
The Perfect Halloween Twist on the Leakproof Bag Experiment
You won’t believe how much fun it is to stick pencils into a Voodoo doll. When the pencils are removed, the water pours out of the holes, delighting the kids.
What you will need to make a Voodoo Doll Leakproof Bag Experiment
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Draw the outline of a person onto the clear side of the bag. We colored our doll green.
Add little voodoo doll details, like a button eye, little heart, and stitches.
Fill the bag with water and seal it up tight.
Take the bag outside.
Hold the bag in one hand, and stab it quickly with the pencil. Make the pencil go through both sides of the bag.
After all the pencils are through the leakproof bag, ask the kids why they think the bag isn’t leaking. Discuss the science behind the leakproof bag science experiment. Ask the kids what will happen when the pencils are taken out.
Take the pencils out and watch the bag slowly empty.
Your kids might like squeezing the bag, or jumping on it like mine did.
Leakproof Bag Science
Plastic baggies are made of plastic polymer chains (they are similar to slime!). When the pencil is forced through the bag, the polymer chains cling to the pencils, preventing much of the water from leaking out. If your pencils are sharp enough and you work fast enough, you can keep any water from leaking out. When the pencils are removed, the opening is too big to close up, so the water all leaks out.
Want More Halloween STEAM? (Science, Technology, Engineering, Art, and Math)
Download our free printable Halloween STEM activities calendar!
Find more amazing Halloween STEAM activities in the STEAM Kids Halloween book!