I have a 3-month old male Collie puppy. He’s a very hyper dog, and gets exceptionally excited to see his people, but shows his excitement in constant biting/nipping of hands, legs, sweaters, pants, etc. He jumps and grabs my coat, sweater, hand, or whatever is in his way, with his teeth. He’s drawn blood many times. A firm no and a loud OUCH do not work. He stops for a second, and then goes back to biting. Substitution with a toy does not work. He will chew on a toy for a second, and then go back to grabbing my arm, etc. It’s gotten to the point where it’s down right annoying. I’ve tried so many things to get him to stop, but he just won’t. He even bites instead of licking when he’s showing affection. What can I do?