Ok I need to know if this is normal - my 10 month old F1 is chewing everything. I just bought a Kong and a tire that has not been destroyed yet. He just seems to be chewing and mouthing a lot and I didn't know if that is normal for a dog his age. What do you do to stop the dog from mouthing and jumping on company? I have been firmly saying not sit, but sometimes the mouthing continues. Help?