We are trying to transfer our 1 year old son from formula to milk, then from his bottles to sippy cups after. He was fine the first two weeks as we went from full formula to ¾ formula and ¼ milk for a week, then ½ formula and ½ milk for a week. The past three days, he will accept his morning and evening bottle, but refuses his other two during the day. I'm not sure why he has started this. Our main concern is having him become too dehydrated as he still does not regularly drink from his water with a hint of apple juice sippy cup throughout the day, and when he does it's usually tiny amounts.