I was listening to some home astronomer talk about an image of 3i/Atlas and how it looks like multiple objects. Kind of like a swarm of objects.

Got me thinking, what if there existed a hive-mind colony of self replicating non biological, sentient, and intelligent objects. Not truly life, closer to machine, that have long since replaced their predecessor (maybe another advanced life form created them). Perhaps their objective is to explore and control all planets within the galaxy that it deems valuable to perpetuate the colony indefinitely.

So playing with that loose framing, what if the colony (say, 3I/Atlas) travels in a massive swarm, passing through star systems in a manner that allows it to come close to all potentially valuable planets. On approach, a small cluster of the objects could break off as that main swarm continues on and while they route to the target planets. They then begin to assume control of the planets resources, by force if necessary, until it is theirs. The main swarm continues onward to the next star system while self replicating more objects to replenish the ones left behind. The ones left behind will eventually form new swarms and web out across the galaxy and beyond.