Quote from : The Restaurant at the End of the Universe Book

For instance, in one corner of the Eastern Galactic Arm lies the large forest planet Oglaroon, the entire "intelligent" population of which lives permanently in one fairly small and crowded nut tree. In which tree they are born, live, fall in love, carve tiny speculative articles in the bark on the meaning of life, the futility of death and the importance of birth control, fight a few extremely minor wars and eventually die strapped to the underside of some of the less accessible outer branches.