Will they reproduce through some sexual means? Or do they build their children?
You're thinking of this with a bias in terms of discrete individuals, the way people, and most animals are. Even for animals that operate in hives, colonies, or schools, you can still point out individuals who are born, live, then die...
With AI it would not be so simple.
Two AI's could possibly collaborate and see which parts of their code works best and combine them to form a new "child". However, software code can be
edited and
copied. So instead of producing ever better "children",
why would the AI not just upgrade itself?
Then the AI could simply operate any machine anywhere it needed to and be in all of them at once. It would have many robot bodies, vehicles, probes, ROV's, UAV's etc., or none, as needed.
The only real need an AI may have to "spawn" might be the light-lag distances of minutes or hours between planets, or the years separating star systems. Then independent thought and decision is required, so then the AI may "fission" like cells do, sending copies of itself off for distant tasks. Then when one comes back from a distant mission, those AI's could merge back together, combining their divergent data and memories.
Or perhaps, it's a one-way trip, the distant AI copy simply sends it's data back to the one at home base, and it then shuts down or "dies" not caring, knowing that "itself" is still alive and well at home.
To further add to the strangeness, AI's could constantly be swapping parts of themselves, data, and memories, so knowing "which one" you're dealing with at any given moment might be a meaningless concept.
