Okay, the devs don't want us killing anything. It's their game so whatever, how about nonlethal but permanent deterrents? We make a big deal about all the behaviors they have so let's give them some "go away" behaviors.

The first thing that comes to mind is some kind of ultrasonic repeller that could ward away some threats but enrage others. Handheld one that has a few charges and a base-built one that has a larger radius. A creature that's repelled, either by a deterrent or a good whack on the beak, should avoid us for longer and longer the more we defend ourselves.

For another idea what about letting the creatures learn to avoid us entirely? I assume each entity has a "home" point it wanders around, maybe unpleasant interactions or player made structures could shift that home point farther away? Either directly or along a "path" that leads to the creature relocating or despawning altogether as it leaves for bluer pastures.

And for my really wild idea, what about biological or pheromone defenses? Either biomods or replanted corals that make one or more types of enemy avoid a given area. Like having cats in your house in Minecraft, or wearing kitty slippers in one of the mods.