It is hardly possible to open a newspaper these days without coming across a listing of the richest people in the UK, in the world, in the solar system...not to mention the endless profiling of Internet millionaires and the obscenely wealthy of all types - from Posh and Becks to Bill Gates. In the footsteps of David Attenborough, Richard Conniff sets out to try to understand the peculiar behaviours of this strange species, setting them in the context of the behaviour of other animals, from mice to flies to baboons.