For if a woman does not cover her head, she might as well have her hair cut off; but if it is a disgrace for a woman to have her hair cut off or her head shaved, then she should cover her head. Corinthians 11:6. Catholic nuns do not wear it out of habit but it's a must. Why does new a nun cover her head? How is it a habit for her? A habit is something you usually do and she is new. Also all other women are NOT average or ordinary.