I am the owner of a 10 month old Bernese Mountain Dog who is still in the mouthy puppy stage (Berners take a long time to mature). The other day, Bodi and I met a gentleman who breeds GSD's. My pup greeted the man happily, as he does with everybody, and then started to gently mouth the man's hands, again as he does with everybody. I thought this was just the remnants of the puppy stage until the gentleman voiced that this was called "Culling." He went on to say that his GSD's do this all the time no matter what age and it is a sign of affection. Has anybody ever heard of this??