In Metroid Prime 2, if you wait long enough in the Great Temple's Energy Controller Room, U-Mos will play with the moths in the room by summoning a ball of light. It makes this Troper wonder if the Luminoth kept those moths as pets.
He might simply feel a kinship with them, or perhaps sees them as his ancestors. Perhaps he sees it as playing with the grandparents?
The fact the Luminoth are actually grateful to Samus for everything she's done for them. Even the dead ones show respect to Samus for her heroics!
In Prime 3 you can access an observatory and scan numerous planets, including Tallon IV and Aether. In the case of those two, you'll learn that Tallon IV is recovering from the Phazon infestation, and the Luminoth are rebuilding their civilisation on Aether. Feels good to know that Samus really made a difference on those two worlds and that she can save planets just as well as blow them up.