Bear scratching his back on a tree

The Engineering Challenge

Design and create a back-scratching tool that will reach a pesky itch.

Have you ever had an itch that you couldn’t reach? Maybe you found a handy tree or a really long stick. Whatever you used or did, you used a tool that needed to:

  • Stay together

  • Reach the unreachable spot

  • Be sturdy enough to scratch the itch without breaking

In this activity, you’ll find items and test them to see if they make a good back scratching tool or not. 


  1. DESIGN: Think of three to five things that you could use as materials to build a back-scratching tool. Making a drawing or describing it to someone might help you understand what materials you will need.

  2. CREATE: Build it! If your tool idea is made up of more than one item, try different ways of attaching those items together, like tape or ties. 

  3. TEST: Test it! Try out your tool on yourself, and ask someone else to try it, too.

  4. LEARN: Did the tool scratch the itch? Did it stay together? Was it strong enough? What could you change?

Change a part of your design or do something completely different. Keep creating and testing.


You can use practically anything for your back scratcher. Try long items, multiple short items, items of different shapes and densities, whatever you can imagine! Think creatively and find out through trial and error what works and what doesn’t.


Design a tool that:

  • Folds up to fit in a pocket

  • Scratches two places at the same time

  • Is hands-free

  • Acts like a roller

Backscratchers like the ones dairy cows use are one of the many tools that have been engineered to keep farm animals comfortable and clean.