He left his mum and siblings waaaaaay too early. He had no chance to learn any canine communication skills and that is why he acted as he did at the puppy party. Ask your vet to recommend someone who can help you to socialise your pup with older pups or adults that are good with puppies and won't hurt him whilst teaching him some canine skills. Best not to let him do that to another puppy again for the time being.
i.e -Ignoring him, putting him in another room, making loud noices, spraying with water - nothing seems to calm him down.
All of these things are likely to make normal puppy biting become more problematic.
Ignoring him is a wasted opportunity to teach him how to play appropriately, so is putting him in another room. Making loud noises could frighten him or increase his excitement levels. Spraying him with water will have the same effect and will also teach him not to trust you.
This is a recent thread on puppy biting, also an eight week old pup. Just ignore the last two posts on that thread.
http://dogchat.co.uk/phpBB2/viewtopic.php?t=6424&highlight=
