Here's some theories to answer a few questions . . .

Rating: Null/10 (23 November 2002)

********* SPOILER *********** DO NOT READ IF YOU HAVE NOT SEEN THE MOVIE *********
I just got the movie today and watched it with 2 of my room mates. We had a few theories that make a LOT of sense about the aliens, why they are there, and how they survive.
1. The planet was originally inhabited by other creatures, but these new aliens landed on the planet during a time of an eclipse (which could last years).
2. The new aliens reproduce much like a cicada using larvae that remain underground until they mature. There is a breed of cicada here that takes 17 years to mature and stays underground until it is ready to come above ground. During that time, millions of these new cicadas come out and are eaten, killed, etc, but a lucky few remain and lay eggs for the species to continue. I feel like this is how the aliens in PITCH BLACK survive. The glow in the dark "slugs" are actually alien larvae that need many years to mature. They glow in the dark to keep the adult aliens from eating them (since they glow, they would hurt the adults). Makes good sense.
3. What do the aliens eat, you ask? Well, each other. Since this is a sci-fi movie and we are to assume that since this is an alien world (and may not even exist in a universe where are laws of physics and nature apply), anything can happen. These aliens, it is my theory, eat each other. It's one hell of a theory, but it's possible that they sacrifice themselves for the good of the species.
Well, that's my little run-down. I really liked the movie and thought it was one of the best Sci-fi movies of the past 10 years. Science Fiction is lacking a big SMART movie, but Pitch Black is the best Alien sci-fi movie I've seen in years. What else can compare? STARSHIP TROOPERS? I think not.