A hole in the center of the nipple may be a milk hole, which is there to allow milk to flow out during breastfeeding, or it may be the result of an indented nipple. Breast holes are openings in the milk ducts on the nipple, and they vary in size from nipple to nipple. There are usually individual variations; in most cases, the breast holes are relatively small and evenly distributed, and in a few, they are larger. Larger boob holes may be the result of two neighboring boob holes fusing together to form a single boob hole, which increases in size. A hole in the center of the nipple may also appear as an inverted nipple, associated with genetics or defective ductal development. The size of the milk hole has no effect on breastfeeding activity. Inflammation, blood spillage, pain or other discomfort is recommended.