My iPhone 5s rattles internally when I shake it. (it's not the home button)

Question

I've only had my iPhone 5s for 2 days but I just noticed that when I shake it, there is a rattling sound coming from inside the phone. I've done some research on this and found similar complaints from other people who also said their 5s rattles, but the big difference between their complaints and mine is that the majority of other people's complaints is that their iPhone 5s rattles from the Home button which seems to be accepted as a normal thing, while my iPhone 5s' Home button does NOT rattle when I shake it, and the source of the rattling sound is internal, behind the screen. It sounds like some small piece got dislodged and is now moving around freely when I shake it. It also seems to come from somewhere near the top half of my phone, not the bottom.
Obviously I'm a bit concerned about this, especially since this is a product by Apple, which is not known for shoddy build quality (yes, even despite that their products are assembled in China, Apple still tends to have good build quality).
I'm not overly OCD, but when things rattle it bothers me because 1. It's simply annoying and 2. It's only normal to assume that something may have broken inside and now I have doubts whether my brand new iPhone 5s is even working at 100% or not.
Does anyone else have the same problem I have? Please don't reply with Home button issues as I've stated clearly that my issue is NOT coming from the Home button but rather elsewhere, internally. If you are knowledgeable about my situation please let me know what the problem is and how I can resolve it, thanks!
If it matters at all my 5s is the gold one with 32GB.

Answer 1

It will be the camera, the lens need a moveable bit so it can autofocus.
It was like that on the iphone 4S too.
Some rattle louder than others but its nothing to worry about and Apple won't change it as a brand new one will also rattle.