The Dark Side of The Mirror

According to this New Scientist article, dark matter could have its own force for interaction with other dark matter and could give off it's own form of light that would only interact with (be visible to) other dark matter. There could be whole dark worlds in the middle of our universe with dark-life that we would just pass right through if we flew through their area. To them, we could be the dark life forms that they couldn't see. Pretty interesting.