nipping or clashing teeth

Question
My wife and I were wondering if this was part of the herding instinct. She doesn't bite like, just kind of nipping.

Answer
Teeth gnashing is something that occurs in all breeds and is normal.  Herding breeds may be especially prone to it, as they are "high drive" dogs and can get excited easily.  The only time you would want to worry is if she is inappropriately putting her teeth on human skin.