I dont want to sound like a nut, but my boys do everything together.
Sleeping, eating you name it, they will even often sneeze and cough at the same time. I suppose it could just be coincidence, sneezing because of dust... looking in same direction at same time because of a noise I didn't notice... but I dont know it just seems... like maybe they are really do run on the same clock so to speak.
Don't get me wrong they have completely different personalities even at this age, we call our second twin "old man" because he is always so serious where as his brother is always smiling. But as far as the physical stuff, anyone else experience this? Did it lesson or go away any as they got older? I find it super cute, but I have to say it is synchronized enough to have kind of taken a few visitors off guard enough to comment on it.