Hey Pongo. I believe Wick and your bun are going through similar changes at the moment! Wick is around 4 months old and this behavior began to crop up more often.
A lot of times (especially when you’re petting them and they enjoy it), rabbits will “nip” at you, to groom you in gratitude. Rabbits are used to grooming fur, so they like to straighten fur by clawing or licking, and they also nibble at any hard things they perceive are “stuck” to your fur. This is why your bun may be more likely to bite at your finger nails, joints, and your pinky toe if he gets the chance, because he perceives the nail as something that needs to be removed or flattened (my pinky toe has experienced this unfortunately, haha). I had to teach Wick that this is something that actually hurt me a lot (not really, but just in case if he interacts with people with low pain tolerance). When he’d nip, I’d retract my hand/foot away and usually make a whining, “ow” sound. I’d still pet him and cuddle with him when he’s grooming me gently, but when it’s more intense, I let him know I can’t really handle it. He seemed to figure it out, so he just licks now. For the digging, I just lift his paws up temporarily so he stops.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.