What's the reason behind the porcupine quills ornament?

The messenger of survival: harvest or hunting is the spinning pig.

Pigs-spiders didn't have fists in the beginning of time, when the world was young. In a forest, a bear wanted to eat the dough of the spinach pig, but the pig took refuge in the cup of a tree. The next day, the spinning pig realized how the thorns bothered him, and he had a great idea. He took a few branches of thorns, put them on his shoulder to cover himself and waited. The bear jumped onto him and wrinkled like a ball. Injuring himself with thorns, the bear had to resign.

Nanabozho, who had witnessed what had happened, called the pig spino and questioned him how he had learned that cunning. The spinning pig replied that after having suffered punches on his body, he thought he could use them as a weapon, as he did not want to continue being the victim of the bear.

Nanabozho took some branches of the thorn and mixed it with clay on the spine pig's shoulder, clawing his thorns into the clay and turning it into part of his skin. On returning to the forest, the wolf appeared and, unaware of his fate, attacked the little animal and wounded himself with his thorns. When the bear saw the spinning pig, he didn't come near, because he knew how his weapon worked. As a result, all thorn pigs have lice.