The most common cause of migration is sleeping on your jewelry (especially with fresh/healing piercings). Another big cause of migration can be from an unsuitable or insufficient tissue being pierced, or if your jewelry is too small in diameter, thin gauge, or of poor quality.  Migration and rejection can also result from using a harsh aftercare product, following poor health habits, or experiencing excessive physical trauma or emotional stress during the healing period. Unfortunately, sometimes a piercing will migrate or reject for no known reason, even when everything is done properly. This is simply a risk of placing a foreign object through your skin: it may not stay in the desired position.