I noticed that you said the child is only happy when he is being fed. If mom and dad do that constantly at home and always let him have food nearby or sit in his chair when he is awake "just to keep him quiet" then what you are seeing is the same behaviour at daycare. I probably would ask parents to explain what they meant by that statement and what they do about it. They may not even realize that they are doing it and think child needs access to food all day.