11mo DS bites, pulls hair, pinches and scratches people - me, OH, his big sister, childcarer, anyone within striking distance really. He giggles as he does it. I've tried ignoring it, putting him down and avoiding eye contact, telling him "No!" very firmly indeed, all sorts. But still he does it. He might crawl quietly up behind you and suddenly bite you on the back of the leg, or he might come to you for a cuddle and a snuggle and you think you are having a lovely time with him all smiley and then he grabs your hair with both hands and opens his mouth to try and eat your face! Why on earth does he do this, and how on earth can I stop it! I find it a bit annoying, but 4yo DD obviously finds it a bit more distressing to be bitten or scratched, and before you know it I have 2 wailing kids.