We got our mini Rex from a pet store 2 weeks ago. It was said to be about 4 months old and they told us that it was "too young to determine gender." Well, I'm not sure if that's true or not but it was in a cage with 3 other rabbits that were all around the same age. We still don't know if we have a doe or buck but it has been very sweet and easy going up until the last few days. It has started biting us hard enough to break the skin and won't let me hold it. Any ideas what might be wrong? Is this just normal behavior? Could it be a pregnant doe? I'm taking it for a check up on Tuesday with a vet that specializes in rabbit care but I wanted some opinions in the meantime.