You are confident br in your babywalker br gliding like a ballroom dancer br among the toddling two-year-olds. br br Quick as a trained assassin, br a child of maybe nearly three, br comes running up – and takes your little hand. br You smile... br he bites... you scream... br I'm there to comfort... br br it's your first lesson br in the unpredictability br of human contact br in a dog-eat-dog world.