Bury head in the sand

...Like an ostrich,burying head in the sand is ridiculous but anyone might do so. Japanese use similar idiom too "you hide only the head ,but not the hip.Evil thing can't be hidden.頭隠して尻隠さず"Recently this is often used as follow meaning"If only you hide the face,you behave shamefully without discretion."
An ostrich has no sense of shame,so of course it is only for a security to bury head in the sand. In English,this idiom means to refuse to confront or acknowledge a problem. To face a problem may be equal to use discretion and to be modest.