A little more on the research - http://www.exeter.ac.uk/news/featurednews/title_488900_en.html http://www.exeter.ac.uk/news/featurednews/title_488900_en.ht... i

A little more on the research - http://www.exeter.ac.uk/news/featurednews/title_488900_en.html http://www.exeter.ac.uk/news/featurednews/title_488900_en.ht... including why it's difficult to do this in the wild. And some earlier research http://news.bbc.co.uk/1/hi/8631486.stm http://news.bbc.co.uk/1/hi/8631486.stm with video.