Birchbark baskets are often embellished with dyed porcupine quills. They painted their skin skirts or decorated them with porcupine quills. Bee stings, porcupine quills, and animal bites rarely penetrate their skin. They embellished hides with dyes, paints, beads, and porcupine quills. These are reduced to stiff, keratinous quills, resembling porcupine quills, with no barbs. The scrolls were written in Hebrew dialects with bird feathers or quills. Quill awards are awarded by the Quills Foundation. Featherbone was manufactured from the quills of feathers. All suffered from some disability, mainly caused either by gunshot wounds or porcupine quills. Some varieties of domestic pigeons have modified feathers called "fat quills". The quills and guardhairs of porcupines are used for traditional decorative clothing. Keratin is a structural protein mainly found in hair, nails, hooves, horns, quills. Embroidery may also incorporate other materials such as pearls, beads, quills, and sequins. Their quills harden soon after birth. The hedgehog's back contains two large muscles that control the position of the quills.