Halloween STEM: Flapping Bat Wings
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Make a bat that can actually flap its wings with this fun Halloween STEM activity!
Using two different sizes of straws and a simple sliding mechanism, kids can build a paper bat whose wings move up and down. It’s part Halloween craft, part engineering challenge—and a fun way to explore how moving parts work.
Our original flapping bat activity was inspired by Stellaluna, a favorite bat-themed picture book, but you don’t need the book to make the project.
Download the free printable bat template below and build your own!
Flapping Bat STEM Activity
The secret to the moving wings is in the straws.
You’ll use two plastic straws with different diameters, with one narrow enough to slide inside the other. When the outer straw moves back and forth, it pushes and pulls the sections attached to the bat’s wings.
It’s a wonderfully simple mechanism for kids to build and experiment with.
Supplies
You will need:
- Printable flapping bat template
- Scissors
- Tape
- One regular-sized straw
- One larger straw, such as a smoothie straw
- Crayons, markers, or colored pencils if using the black-and-white bat
The important part is choosing two straws that can slide easily inside one another.
How to Make Flapping Bat Wings
1. Print and Cut Out the Bat
Print the bat template.
Kids can color the black-and-white version first, or you can use the colored template to skip the coloring step.
Cut out the bat.
2. Cut the Opening for the Straw
Carefully cut a small slit in the center of the bat as shown in the pictures.
This is where the smaller straw will pass through.
3. Attach the Smaller Straw
Cut a slit approximately one inch long into the end of the narrower straw.
Slide the straw through the opening in the bat.
Separate the cut sections and bend them outward. Tape them securely to the bat as shown.
4. Prepare the Larger Straw
Shorten the larger straw. I cut approximately one-third of ours off.
Next, cut a slit into the straw extending about halfway up from one end.
5. Add the Outer Straw
Slide the larger straw over the smaller straw.
Bend the cut sections outward toward the wings and tape only the ends in place.
Make sure you don’t tape the mechanism so tightly that the straw can no longer move.
Slide it over the top of the smaller straw and bend out the cut sections. Tape at the ends only to secure.
6. Make the Bat Flap!
Now for the fun part!
Slide the larger straw back and forth and watch what happens.
Your bat’s wings flap!
What’s the STEM Behind the Flapping Bat?
This project gives kids a simple introduction to mechanical motion.
Your hand moves the straw in one direction, and the sliding pieces transfer that movement to the bat’s wings.
Have kids look closely at the mechanism while they move the straw.
Ask questions such as:
- What happens when you push the straw?
- What happens when you pull it?
- Which parts of the bat are moving?
- Where does the movement begin?
- What happens if the tape is placed in a different spot?
- Can you change the design to make the wings flap farther?
That last question turns a cute Halloween craft into an engineering challenge.
Let kids modify their bats and see whether they can improve the movement.
Learn About Bats, Too!
This is also a great activity to pair with a study of real bats.
Before building your flapping bat, look at pictures of bat wings. Unlike a bird’s feathered wings, a bat’s wings are made from a thin membrane of skin stretched over elongated finger bones.
Kids can compare a real bat’s wing structure with the simple paper mechanism they created.
You could even ask:
Does our paper bat move its wings the same way a real bat does?
That opens up a great discussion about the difference between a model and the real thing. Models can help us explore an idea even when they don’t perfectly reproduce how something works in nature.
Pair It With Stellaluna
We originally made our flapping bats after reading Stellaluna  by Janell Cannon.
It’s a natural book pairing for this activity and gives you an easy way to combine literature, science, and engineering in one lesson.
Read the story first, learn a little about real bats, and then build your own flapping bat.
Get the Free Flapping Bat Template
Ready to make one?
Download the free printable Flapping Bat Wings Template here.
Try the Butterfly Version
Once kids understand how the mechanism works, try my Flapping Butterfly Craft using a similar idea.
It’s a fun way to revisit the project during another season and compare two very different flying animals.
More Halloween STEM Activities
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Pumpkin Solar System Science Project
Pumpkin Slime Science: A Fall Sensory Experiment for Kids
Twirligig Pumpkin Paper Spinner Toy
Pumpkin Fractions Printable Math Pack
