[@Oraculum]
Ezra does indeed have such artificial ecosystems within.

As for drones you can define them regionally as you wish.

Around the system you have the common drones that have easily definable purposes (mining, monitoring the natives and interlopers, repairing ancient structures, carrying other drones, defending sealed habitats and the 'depths' etc.) while the custodian players can make more unique and/or esoteric drones.

IC-wise i'd expect most peoples to be used to the common drones, it'd be no more weird than seeing a bird fly overhead and they're remarkably quite and docile.  Even shooting them yields no response (and if damaged enough, they just disintegrate into paste).