That's an interesting definition for a soul. Soldat's not sure what they think about it-- it's something that could probably be ascribed to themselves, isn't it-- so they don't address it yet. Instead they say, "Earth has monkeys. I think they have hair, or fur, though. Like this." They reach around and pull their ponytail over one shoulder. They're pretty sure she's referred to their own hair as plumage before. "Is this what you mean?"