Five years ago, on a remote island in Wales, University of Oxford scientist Annette L. Fayet spied a puffin doing something she had never seen before. The bird, floating on the seawater beneath a cliff, held a stick in its beak. It began to scratch its back with the stick - the puffin, as Fayet watched, was using a tool. Fayet, a puffin expert who studies how the birds migrate and feed, wrot