An Observation *SPOILERS*
Despite the typical illogical behavior of separating to die off alone I dug the movie but I couldn't help but come to the conclusion that Dick Speck is actually--
--a PREDATOR!!!
1. Looking directly at the 'ghost' and NOT seeing him - Predator
2. Dragging bodies up into the ceiling (i.e. treetops) - Predator
3. Killing it's victims close-up with slicing weapons - Predator
4. Need i mention it's clucking noise eerily reminiscent of a Predator call. I just did.
I can't explain the rape scene but I wish that was left in the cutting room floor anyway, although it wasn't as exploitative as it could have been.
Anywho, Dick Speck is actually a Predator-in-training left on earth to hone it's hunting skills.
Gentlemen, you have your sequel. You're welcome.