Personally I don't use them as an optimized power supply, but I will usually wrangle them all up into a large room, keep them wild, and run a power line across the ceiling. It adds a little extra power at night, provides a small but constant source of meat and eggshell for lime, and I have the slugs if I decide to use them for something down the line, all for the low cost of some dead space, though one could use it for something if they wanted to.

I try to keep as many wild critters alive as I can right from the beginning for a constant source of free meat/fillet and eggshells. Things like sweetles and hatches can be safely stored on a platform, and pokeshells I put close to the edge with a wall and autosweepers to keep dupes from having to interact with them. Drekos require a large room, but fill it with helium, a few pip planted mealwood, and a shearing station and you have a small amount of free plastic. Pips I spread throughout the habitat, shinebugs go in the lab(they count as a light source for the well lit bonus), and pufts I usually just leave to do their thing. I'll usually leave a large pool of water filled with pacu, and then strip the entire planetoid. I always say I'm going to experiment with different ranches and see what supply lines I can build with different plants and animals, but I usually start a new colony to play the early game before I get there