Mine has never bit an adult at any time. She is always good to adults. But we cannot let any child near her. Any child under about the age of 10 will be bit. She has never broken skin because we have been careful to be very close by when a child is near. However, she will snap at them if they try to pet her. Every time! None of the children have done anything to her, and no child has ever hurt her. Usually I am holding her at the time, and the child has been very polite. This seems to be that unpredictable terrier coming out.