My dd2 (2 and half) has started biting. It's usually out of frustration, if things aren't going her way, and it is usually my poor dd1 who gets it. She has a big bruise on her arm from a bite she got yesterday. I tell her off, but she just bursts into tears and asks for a cuddle. Several people in rl that I have asked have told me to bite her back!! But I really don't want to do that!! Any advice? TIA