I have two cats aged 7.5 mos and 2.5 mos. Both are on dry kitten food. All the kitten foods seem to say that cats should be on them till 12mos or so. What do i do when Lucky (the oldest) should be switched to adult food, but Rambo (youngest) will still be a kitten? They both eat of the same dishes and won't eat if they are put in separate rooms. Is it alright to keep Lucky on kitten food for longer, or switch Rambo sooner? Or am i worrying for nothing?