In Ridley Scott's 1979 movie 'Alien', after Ripley rigs the ship to self-destruct she proceeds to the escape pod, all the while the ship announcing that it has been rigged to blow and commencing a countdown.
Ripley reaches the escape pod, only to find the xenomorph already there. The xenomorph sees her, she freaks and runs back to the area where she rigged the explosives to try to disable the destruction sequence (which she couldn't). Strangely, the alien never followed her or gave chase, instead tucking himself into the escape pod while she was trying to reset the bomb.
This has always bothered me. For me, this reveals a predatory mind of the highest order. Could it be that the alien anticipated or understood the self-destruct sequence? It never bothers to follow Ripley upon the original rendezvous at the escape pod, even though it would have been easy for the alien to destroy her. Also, to further support this argument, after Ripley's initial revelation that the alien was also tucked away safely in the escape pod after blowing the mothership, the alien seems to be content just laying there idly, not showing any form of aggression towards Ripley until she tries to smoke / freeze it out.
Could it be that the alien was intelligent enough to know Ripley would attempt to return to earth or rendezvous with another ship, thereby ensuring it a steady supply of victims?
Considering this movie came out in '79, it's still remarkably watchable today, even raising questions I had not considered upon my original viewing as a youngster.