I’m imagining a pool snail

“What is my purpose?”

“You crawl around outside and smell for astronaut wizz.”

One thing that’s rarely discussed about spaceflight is that for the foreseeable future, it will have to happen without the animals that humans rely upon on Earth. I think this will expose just how strong that reliance is in some areas.

I wonder about what happens to gut micro biomes

They'll standardize so that everybody has more or less the same stuff.

...or the scutters on Red Dwarf.