Dear Polite Librarian: If one has used up one's supply of mace on the patron who asked if one would like to "get a gander at Mr. One-Eyed Tiddywinkles," is it acceptable to simply stab the assumed potential serial killer patron in the ear with one's pencil stub? ( I am new to the library field and do not wish to alienate either my bosses or my customer base with my neophyte gaucheness.  Thank you in advance for your help.)