Biting is a way some kids express anger or stress, says Alice Sterling Honig, Ph.D., professor emerita of child development at Syracuse University in New York. But you need to nip it in the bud, so:
Say no. Immediately (and firmly) tell her "no biting!" If she bit another child, show her the right way to act by caring for the other child.
Don't bite her back. It may be tempting to show her what it feels like, but this will signal to her that it's okay to bite.
Give her other ways to express herself. Teach her simple phrases like "want that," "my toy," and "mine," so that she can use words --instead of teeth --to make a point.
Slow things down. A constant "on-the-go" feeling can stress toddlers out. Longer, more relaxed feedings and bathtimes, for instance, may help her feel calmer.