I have the same problem with Mimzy, when I remove him from his pen for his grooming and exercise, I usually hold him on my chest for a little while to help him relax. Prob is, once he relaxes, he starts the digging and biting. He put a good notch in my belly once and I turned him around and told him “No.” firmly and he scrunched up till he looked like a chinchilla and fixed me with those big brown eyes like I was the meanest bunny mommy in the world. So I had to laugh a bit and ruffle his fur to help him understand I wasn’t angry with him. Honestly, he a touchy little bun!
My bigger problem is the scratching. If he becomes nervous while I’m holding him (usually during the transfer between the xpen and his cage) he tends to struggle, and since I am afraid he will wind up hurting his back, I let him scratch the heck out of me until I can get him in the cage again. If I try to contain him, he only struggles harder and one time I almost lost him as he tried to do a header out of my arms. >_<
So the biting is courtship behavior? But my bun is neutered…why would he be doing this?