There is hardly a better example of this way of thinking and knowing than the work of Miriam Rothschild (19°8 - 2005). She considered herself no scientist, yet had published over 350 research papers, 150 of them about fleas. She held several honorary degrees. In a Radio 4 interview (1997), she commented, 'I get so interested in everything; I've always been free to play.' At the age of 4 she had a ladybird collection, as well as quails and worms. As the only applicant she won a research scholarship to Naples: 'The sea fauna were so beautiful, incredible jellyfish."The next thing I got obsessed with was fleas; you could forget everything observing fleas.' If this was play, where did it lead? Miriam Rothschild discovered some amazing connections in nature: heart poisons collected by butterflies, oestrogen of the doe rabbit needed by the mixi flea (giving us some idea of how the contraceptive pill works), and her 'Eureka moment' was to discover how fleas jump by the release of a force, click mechanism. 'I saw it in my mind's eye ... that's how it happened. Everyone can be a naturalist, all you need is interest.'