In nature, the ability to sense danger is often the difference between life and death.
Take the herd of antelope grazing peacefully on the sun-soaked prairies of Africa. Danger stalks these beasts constantly. They are the fillet mignon of lions, cheetahs and other carnivores prowling the plains in search of fine dining.
For the antelope, staying alive is a function of their ability to sense danger and react quickly.