How we cite our quotes:
Pipkin, some way away from Hazel, crouched at his ease between two huge rabbits who could have broken his back in a second, while Buckthorn and Cowslip started a playful scuffle, nipping each other like kittens and then breaking off to comb their ears in a comical pretense of sudden gravity. (13.19)
When Hazel's group meets Cowslip in chapter 12, they are really suspicious and cautious for a while. But by chapter 13, everyone is friendly and playful. But notice how Buckthorn and Cowslip are play-fighting; and notice how the narrator reminds us that there's the potential for danger all around with Pipkin near some big rabbits who could seriously hurt him. Even when everything seems peachy, violence is hard to get away from.
He turned and dashed back through the nearest gap in the hedge. On the instant, a fearful commotion began on the farther side. There were sounds of kicking and plunging. A stick flew into the air. Then a flat, wet clod of dead leaves shot clean through the gap and landed clear of the hedge, close to Hazel. The brambles thrashed up and down. Hazel and Fiver stared at each other, both fighting against the impulse to run. What enemy was at work on the other side of the hedge? There were no cries—no spitting of a cat, no squealing of a rabbit—only the crackling of twigs and the tearing of the grass in violence. (17.37)
When Bigwig gets caught in a human snare, all we know at first is that some terrible violence is going on. We hear the sounds of a body jerking around, we see the bush shake—but we don't know what's going on. This is almost like a horror story, where we don't know what terrible thing is going on behind the bush, so it's natural for the rabbit impulse to be to run away. But they don't (hurray)—Hazel and Fiver run in to help when they hear violence going down.
The story over, the demands of their own hard, rough lives began to re-assert themselves in their hearts, in their nerves, their blood and appetites. Would that the dead were not dead! But there is grass that must be eaten, pellets that must be chewed, hraka that must be passed, holes that must be dug, sleep that must be slept. (22.1)
You could write a story where all these rabbits have PTSD and are haunted by memories of violence they've encountered. But that's not the book that Adams wants to write and he tells us how he's going to avoid that topic right here: Rabbits live in the Now with a capital N. So they may be surrounded by violence, but as long as they aren't being attacked right Now, they're going to move on with their lives. Natural life—eating, pooping, sleeping—is more important than being sad about violence in the past.