"Why do we do this?" Qblhbrp squorpped a contact with its tentacle, launching a full pod of world-conquering robots down to the planet below. "Do what?" Sskqhht adjusted their trajectories to make sure they all arrived. A full complement of robots could self-replicate and secure the planet in three to five years, depending on resistance. Losing even one could spoil the timeline.
"Conquer planets. We send in the robots, five years later we install our governors. What for?" Some of the robots would become unstable. With mutated programming, they acted against their masters' interests.
"So we can rule, obviously." The robots' network let them perform frequent checks on each other, and they ruthlessly destroyed any that strayed from the mission.
"Yeah, but... what's the point? We live, we die, and so do our trillions of subjects. Why reproduce?"
"So our children can rule the worlds we've conquered and conquer more worlds, and their children conquer further."
"If they don't want to?" Qblhbrp stared out the viewport, disconsolate.
"Then we kill them as deviants." Sskqhht drove its war-tentacles into its partner. Below them, the robots fell toward the planet, inexorable, their tests already questing through the network for deviations from programming.