The hole in the nipple should allow the milk to flow in a steady stream of several drops per second when the bottle is inverted.
If the hole is too large, your baby will get too much too fast and splutter; if it is too small, your baby will get tired from sucking before she is satisfied. To make the hole in a nipple bigger, insert a fine, red-hot needle gently through the hole to melt the rubber (stick one end of the needle into a cork and hold it over a flame to heat it).
Sculpted nipples that are shaped to fit the baby’s palate and allow her control over the flow are best.
