Nipping and biting are two different things – if Peach were biting you, she’d definitely be going right through the skin. Rabbits can have ferocious bites, as anyone who’s ever had to separate brawling bunnies can attest. What Peach is doing is nipping you, and as you’ve guessed, she’s trying to tell you something. What, though, exactly, is another question. She could, for example, be telling you “hey, leave off the petting, I’ve had enough for now!” if you were petting her. Or, if you weren’t paying attention to her, she could be telling you to give her some. Or maybe she’s hungry for a treat and a soulful look at you isn’t getting her what she wants. Or if she’s been in a playful mood, she could be doing it just to get a rise out of you.
Fernando, my REW male, has been exhibiting similar behavior for the last month and a half or so during evening play sessions, though it doesn’t usually come out of the blue – in fact, I’ve come to expect it at least once per evening. He’ll usually come up next to me, pause for a second as if gauging my possible reaction, and then nip at my clothing (usually undershirt or socks), or even chew briefly at same. Generally, he only does this once or twice an evening, but occasionally – such as last evening – he’ll do it a lot. From his overall behavior during our evening floor sessions, I’m pretty certain that he’s doing it both for fun and as a request for attention.