Ive got an 11 week old westie pup called Snowy. He keeps nipping and biting kids feet.What is the best way to discourage this

Read this article. Although it's much easier said than done, it will also help a lot if you keep the children calm and not allow them to run about around the puppy. He'll take a lot of his cues for behaviour from them - the calmer and quieter they are the more it'll rub off on him.
:)