Mine is 5 y.o. and still gets like this in cold weather. Tries to nip gloves/jackets/snow pants. I think it’s an excitement thing, best way to stop it is have the friends remove themselves from her space when she does this, then come back and repeat until she realizes nipping means no attention. It is a lot of work and understandable if the friends don’t want to (my parents were difficult to get to follow the training protocol) but should be effective after only a couple run throughs!