User blog comment:SupcommMonroee/Suppy Super Post 7 - Ratios and Numbers! Space Navy Numbers!/@comment-771241-20130512044405/@comment-1743498-20130512131212

National Geographic hypothesized that an alien invasion on Earth would be done entirely by robots. The aliens themselves wouldn't want to risk going out into a hostile atmosphere.

For more complex wars that require unique planning, we can expect to see more organics which are less specialized than robots. So whether the ship is automated or not depends on the situation.