PHASE IV, d. Saul Bass (1974)
In an ideal world, all science fiction films would be directed by Saul Bass, but it's not an ideal world, is it? It's not even halfway there.
Anyway, we have 'Phase IV', one of the most beautiful films ever made.
If you'd like an insight into what life would be like if humans were under the heel of billions of super intelligent alien ants, then you need to take a look at Bass' original ending. It didn't make it into the final cut, as it would have blown peoples minds and ripped a hole in the space / time continuum.