The blue whale is undergoing cosmetic surgery, the dinosaur is being given a spring clean and the elephants and rhinoceroses are on the move. All this before the 7,500 visitors arrive for the day. Behind mahogany doors, away from the public, the scientists beaver away in their own little worlds. Dr David Wragg is trying to record the love call of the cricket. Peter Whitehead is messing about with sprats and Paul Hillyard is feeding his pet tarantulas. He actually likes spiders. "Nobody has ever been eaten by one," he says, "it's just that they have had a very bad press."