io9.com has a great article up in regards to how the aliens came to be. The video is great, but this is the interesting part:
So this really helps explains Christopher’s role in the grand scheme of things and brings to life more of the bug-like background and giving the Non-Humans more character and definition. Although they are called Non-Human, they are starting to act with more Human feelings. Maybe due to their time on earth?
We’ll find out on when District 9 opens this Friday, August 14th.