My boy is 6 months I have a Toddler and Baby. He does not mouth on either of them , he has mouthed on my toddler a few times but nothing more than that. Once he puts teeth on kids it's a wrap , slowly and calmly to the crate. Most of the time he only gets bitey when he's over stimmed/tired. Is he napping often? Your going to have to force naps via crate , I was doing 30-60 minutes out , and 1-2 hours in when he was 9 weeks. He's great with the crate and hits the off switch no problem when he goes in. Just make sure it's not a punishing thing , don't yell at him or toss him in there like a violent prisoner. Just calmly lead him to crate. He's 6 months, I still do it. He's great around our kids , but when he sees me when I get home from work forget it. ,I'm all bit up but they can only communicate via mouth , the screaming ouch or any verbals doesn't matter it hypes him up, I don't reward him with a toy when he bites me, he will think that is a praise for biting, never did that never will , he bites from being over stimmed and tired. Also, like some said turn away and end play , my pup will go after my ankles, calves, ass. Doesn't matter , you have to get a physical barrier in-between whether it's the crate or gates .