I remember hearing this story years ago. 

  They say that the Eskimos, in order to catch a wolf, take a knife and coat it in blood, let it dry and re-coat it, again and again, until there is a thick layer of frozen blood on the blade. Then they take it in the woods and bury the handle, with the blood soaked blade above the snow. The wolf is attracted by the scent of blood and begins to lick the blood from the blade; and as his frenzy increases, he licks so hard his tongue is cut and he begins to bleed: but not being able to recognize his blood from the blood on the blade, he ends up wounding and killing himself by his own blood-lust. 

The application to ourselves is easy.