Did you get scolded for chewing on a ferrule as a child?  We all probably did – it is the metal band around a pencil that holds the eraser on the end.  Meaning “little bracelet” the humble ferrule spends its whole life dutifully performing an important job and most of us never knew its name.  But, my guess is that we all know the familiar squish as our teeth made dents in our pencils. Yep, we were chewing on a ferrule? Or was it just me……