Okay, imagine you live in a really big place called North Carolina. In North Carolina, there are lots of different animals and things that you might see. One of those things is a special kind of tree called a pine tree.
Now, pine trees have special things on them called pitch. Pitch looks kind of like sticky black goo, and it helps protect the tree from bad bugs and other things that want to hurt it.
One day, a long time ago, people in North Carolina realized that they could use this pitch to help make their homes better. They would heat up the pitch until it turned into a sticky, hard substance called tar. They could use this tar to put on the bottom of their shoes so that they wouldn't slip and fall when they walked on the rocky ground in North Carolina.
Now, the people in North Carolina who used this tar on their shoes became known as "Tar Heels". It was a way to show that they were proud of where they came from and how they made their lives better by using what they had around them.
And that's why people from North Carolina are called Tar Heels!