Bad behaviors can result from many things such as boredom, lack of training, separation anxiety, health issues, and much more. If a behavior pops up suddenly and is not normal behavior for your pet, check with your veterinarian to make sure a health issue is not the cause. Obedience training is another great way to curb unwanted behaviors. Check online for local classes. The internet offers many different ideas and tips for do-it-yourself training to help you change those behaviors.