I have one year old girls. One of my daughters keeps biting her sister. Everything I have read talks about the biter being fustrated or stressed- I dont think that is the case. I think she is biting bc she is teething and her sister is right there! I have tried laying plenty of teethers and chewable toys around. I catch her most of the time before it happens. I think they are starting to understand NO, and she certainly understood when I sat her by herself. I try to explain- but sometimes she just laughs at me when I discipline her. I have read to bite her- but that seems counter-productive- if I do it, it must be okay. I have read not to bite her too! I am not biting my child regardless!!! lol Argh.