GSD/Border Collie biting issue
6 week/7 week old puppy seems to have a biting issue. I know he's teething, but ever since we babysat a kid here, he bites way to hard (to the point where he breaks the skin). If you push him away, he'll keep going for the bite. If you give him toys, he'll play with the toy for 5 - 10 seconds then go for the feet and whatever other part of you he can bite.
It was ever since we had the kid here, that he doesn't play with his toys, he would rather bite us now. As I said above, he is biting harder than he usually did 2 - 3 days ago, it would be nibbles and such. Now it's just painful to let him bite you.
Any ideas why he's doing this, is this normal? And how can we get him not to do this?
We have already tried punishing him when he does this, he will stop for 3 - 5 mins then go back at it.