You all know that we use hand movements - like sign language - to communicate with our dolphins. But what do we do with a visually impaired dolphin? Betty is here to demonstrate! The signal for a dolphin to vocalize is a little wiggle of the finger. For Betty we take that same hand motion that she knows so well, and we do it on her rostrum so she can feel it when she can't see it. How did we learn to do this? Nellie - you know Nellie! - who lived to be 61 years old and had failing vision in her