Contrary to popular belief, ostriches do not bury their heads in sand when faced with danger, being far more likely to either flee from the threat or attempt to kick it to death. The myth may have been propagated by Roman scholar Gaius Plinius Secundus through his Natural History, an early and influential encyclopedia of natural science. Book X opens with the false report that such birds "imagine, when they have thrust their head and neck into a bush, that the whole of the body is concealed".
Online edition of Pliny the Elder's 'Natural History', as translated by John Bostock and H.T. Riley, (circa-77 AD)