I assume you mean around the camera, there's a little rattle, I believe it's quite common, happens on mine too and everything works fine, not sure what it is though.

 

I noticed when i first got it that the back case didn't seem to stay closed, had slight press to it (hard to explain). I've just checked and i can't seem to replicate it now. Maybe the back on/off a few times has stopped it.

 

Mine does the same. After reading other threads about this, it seems to be the autofocus mechanism that makes the rattling noise apparently.