I am in shock. DD is normally placid and rational even when she is not behaving very well. We were just in the kitchen and she kicked a ball at DS 4 mos in his nuna. DH said, 'careful DD, your brother is too small to play football.' DD moves on to something else all fine or so I thought. Then she picks up a toy and throws it. DH says, 'Chill out, DD shall we go and play outside?' They go outside and she throws an almighty wobbler, DH picked her up to bring her inside and she just sank her teeth into his arm! I'm shocked, she's still screaming, upstairs, and DH is soothing DS and a bit teary himself. What should I/we do next? This has NEVER happened before.