So we adopted our first dachshund mix about 2 months ago. Generally he is pretty well behaved but he has some issues. he is 2 years old (so we are told) and seems fairly set in his ways. He learn quick though but is super stubborn. Lately we have noticed some biting and aggression when we take away a toy or move him off the couch when he doesn't want to be moved. Any advice on how to get rid of this behavior before it gets out of control??