Apologies if these have been asked before, but here goes:
In the director's edition of the film, the two convicts who bring the dead ox into the kitchens on a cart find a dead facehugger on the cart underneath where they dumped the ox. What was it doing there, and how come the two men didn't spot it when they dumped the ox there in the first place?
And in both versions of the film, just why is the alien killing everyone left and right? If it's task is to protect the Queen gestating inside Ripley, shouldn't it leave plenty of potential hosts for its offspring?