zaza-I heard from pple that some bb refuse to latch when they r introduce to bottles. That's why I choose NUK latex teat so call similar to nipple. initally I couldnt latch my boy, he doesnt know how to latch. then abt 2 mths later I tried latching him, suddenly he can latch. So now i bottle feed him in day time, nite time latch him, he is fine with both ways. I seriously dunno whether NUK teat plays a part or not. I did get another brand bottle(tommi something, cant remember the exact spelling) n feed him but he drank with it very slowly, so I stop giving him that bottle.