I introduced the sippy cup because he won't take a bottle and won't nurse that well anymore. I am just letting him figure it out right now with a little bit of water. I started solids because he is 4 1/2 mon. and he weighs 17 lbs. He can't handle his vitamins( they make him throw up). He does real well with it and he has lost his tongue thrust reflex. He dosen't even make a mess with the cereal. It was the only way I thought to make sure that he is getting all of his vitamins and nutrition. I mix the cereal with BM.