There are many reasons a kitten may not suckle from a bottle. One major reason is that the kitten is too old for bottle feeding and ready to eat wet food. See the Determining Age informational sheet for more information on how to determine the age of a kitten. Two other reasons a kitten may not want to nurse from a bottle include an issue with the formula (not warm to the touch) or the size of the nipple (opening is too small).