Hello! I've read a bunch of posts on here about puppy biting but still hoping for some advice. I have a now 19 week old male yellow lab puppy - he was super bitey when younger, but we are happy that his general daily biting has reduced a ton due to many of the methods I've read about on this forum. Our issue is that he seems to bite (and bites hard) when frustrated and/or when something is happening that he doesn't like. The first example is when we are trying to put on his harness before a walk - he clearly doesn't like this and turns his head to bite our hands - we can avoid this somewhat by putting it on while giving him treats, letting him lick a likimat, etc. Another example is when he jumps on the couch without being invited (which he does often) - if we tell him to come down/try to take him off he bites at our hands. We also have issues with him jumping/biting/humping our legs simultaneously. This happens a few times a day but seems worse at night. He is biting hard at our thighs and calves when he does this. I know there are many posts on here saying puppy biting is completely normal but these don't necessarily seem like the "puppy play nipping" i am used to. This is my third lab and I've never experienced this before. Should I be worried about this behaviour? I should note that he has lost all his front teeth with adult teeth growing in; the rest of his teeth are still baby teeth. Any advice is appreciated!!!