The excerpt represents the core issue or deciding factor on which you must meditate, and is drawn from Expression of Emotion in Man and Animals by Charles Darwin: Impatience is expressed by pawing the ground.
[7] `Land and Water,' 1867, p. 657. See also Azara on the Puma,
in the work above quoted.
[8] Sir C. Bell, `Anatomy of Expression,' 3rd edit. p. 123. See also p.
126, on horses not breathing through their mouths, with reference
to their distended nostrils.
The actions of a horse when much startled are highly expressive.
One day my horse was much frightened at a drilling machine,
covered by a tarpaulin, and lying on an open field. He raised
his head so high, that his neck became almost perpendicular;
and this he did from habit, for the machine lay on a slope below,
 Expression of Emotion in Man and Animals |