We're looking after a 12 week old cocker spaniel and he's responding really well to training but there are a couple of times in the day when he seems particularly bitey and overexcited. He spends a lot of his time with us in the kitchen where he's relatively calm and has access to the garden but in the evening when we want to settle in the living room, he's like a thing possessed - jumping all over the furniture, biting, pulling on clothes. Whenever we sit down in the lounge he does this. Any tips please?