Halloween is the perfect opportunity to test out those design and engineering skills! This amazing Halloween STEM challenge uses just a few simple materials but has a world of possibilities. Transform simple cotton swabs into bridge-building materials with a Halloween twist. A skeleton bone bridge with q-tip “bones” is a creative way to explore STEM.


Explore STEM For Halloween

Get ready to add this simple Halloween bone bridge challenge to your STEM lesson plans this season. We did the STEM boat challenge, now test out your engineering skills, with this easy to set up Halloween STEM activity for kids. While you’re at it, make sure to check out more fun building activities.

Our STEM activities are designed with you, the parent or teacher, in mind! Easy to set up, quick to do, most activities will take only 15 to 30 minutes to complete and are heaps of fun! Plus, our supplies lists usually contain only free or cheap materials you can source from home!

Using inexpensive or recycled items to make cool things allows awesome STEM challenges to be accessible to ALL kids! Plus, this Halloween STEM challenge also makes a fun cotton swab skeleton craft!

STEM challenges with kids are tons of fun and give them a great chance to troubleshoot problems and come up with creative solutions. Great for a variety of age groups too!

Check out all our Halloween STEM activities here!

What Is STEM For Kids?

What is STEM? So you might ask, what does STEM actually stand for? STEM is science, technology, engineering, and math. The most important thing you can take away from this, is that STEM is for everyone!

Learn more about “What is STEM?” here.

Yes, kids of all ages can work on STEM projects and enjoy STEM lessons. STEM activities are great for group work, too!

STEM is everywhere! Just look around. The simple fact that STEM surrounds us is why it’s so important for kids to be a part of, use, and understand STEM.

Interested in STEM plus ART? Check out all our STEAM Activities!

From the buildings you see in town, the bridges that connect places, the computers we use, the software programs that go with them, and compasses for navigation, STEM is what makes it all possible.

Helpful STEM Resources To Get You Started

Here are a few resources that will help you introduce STEM more effectively to your kiddos or students and feel confident yourself when presenting materials. You’ll find helpful free printables throughout.

Get your free printable Halloween STEM challenge!

Bone Bridge STEM Challenge

Make sure to grab these Halloween STEM Challenge cards to add to your maker space.

The Challenge: 

Build a bridge out of only bones (aka cotton swabs) that is a minimum of one foot long and sits at least one inch off the ground or table. Sounds too easy? Or does it!

Many STEM projects use critical thinking skills as well as math, and engineering skills and this one is no exception. Attention to detail is a must and pre-planning is encouraged! This can be either a timed challenge or not.

Time Needed:

30 minutes or more if time allows!

Encourage kids to spend up to 5 minutes talking about their design ideas and doing rough sketches. Then allow 20 minutes for building your bone bridge. Plus, another 5 minutes to talk about the challenge, what worked and what didn’t.


  • Cotton Swabs
  • Tape
  • 100 Pennies


Do you have older kiddos? Add an extra layer to the challenge and, create a specific type of structure or bridge or choose a type to build. Allow them a few minutes to research different types of bridges and draw out a design!

Do you have younger kiddos? Just explore the materials and test how they work together to complete the challenge simply. Set up two blocks or books and have them build a bridge spanning the distance you choose.

Extend The Challenge:

Can you build a bridge that can hold the weight of a roll of pennies or of another pre-determined object?

STEM Challenge Setup:

STEP 1: Give out supplies to each kiddo or group.


STEP 2: Give 5 minutes for a planning phase (optional).

STEP 3: Set a time limit (20 minutes is ideal) for groups or individuals to build their bridges.


STEP 4: Once the time is up, have the kids set up their bridge for everyone to see. Test out the skeleton bridge design to see how much weight it can hold.


STEP 5: If it works for you, have each kiddo share his/her thoughts on the challenge. A good engineer or scientist always shares his/her findings or results.

Ask a few questions:

  • What was the most challenging thing about this Halloween STEM challenge?
  • What would you do differently if you had a chance to try the bridge challenge again?
  • What worked well and what didn’t work well during this STEM challenge?

STEP 6: Have fun!

Why not pair this Halloween STEM challenge with our printable roll a skeleton game!


More Fun STEM Challenges

Here are even more quick STEM challenges that use very simple materials and allow your students or kids to complete fun challenges or projects in a limited amount of time.

Straw Boats Challenge – Design a boat made from straws and tape and see how many items it can hold before it sinks.

Strong Spaghetti – Get out the pasta and test your spaghetti bridge designs. Which one will hold the most weight?

Paper Bridges – Similar to our strong spaghetti challenge. Design a paper bridge with folded paper. Which one will hold the most coins?

Marshmallow Toothpick Tower – Build the tallest tower using only marshmallows and toothpicks.

Printable Halloween STEM Activities Pack

150+ Pages of Halloween-Themed Materials!

This Halloween project pack is suitable for home, school, and group use for kids in grades Kindergarten through elementary but is scaleable for many ages and abilities.

What’s Included:

  • 25+ Halloween theme science and STEM activities with printable sheets, instructions, and useful information all using easy-to-source materials perfect for limited-time needs. Includes a Halloween engineering pack with fun, problem-based challenges for kids to solve!
  • The skeleton activity pack includes building a skeleton challenge and a coding challenge! Try a skeleton bones bridge-building STEM challenge!
  • Halloween theme brick printable activities for hands-on learning with math that is perfect for early finishers or home fun and reinforces basic math concepts.
  • Bonus fun pack includes games and activities to round out your Halloween theme activities such as I Spy, bingo, matching, Would You Rather cards, scavenger hunt, word search, A-Z Halloween hunt, and a coloring page.
  • Halloween STEAM Pack includes artist-inspired projects by Warhol, Lichtenstein, and more!

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