I have made peace with murdering animals. In fact, I have made peace with murdering in general.
I mean... Am I the only one who didn't even concider wearing a disguise in the citadel? Am I the only one deliberately clicking on animals that are still friendly towards me?
Although killing animals seriously cranks up the difficulty of the game. Even if some animals are just level 1 or 2, they can be "in the way" when you're fighting other creatures.
But it's all good. I like it this way.