A Lesson In Horse Sense

A veteran trail horses unusual behavior leads to an important discoveryand a lesson in equine instinct.
Not long ago I had a lesson in horse sense courtesy of my Quarter Horse gelding Bull.
I had been wanting to try my younger gelding on a trail ride so one day I invited a friend to join us aboard Bull an experienced trail horse. We headed up a path that Bull and I had taken many times. But at the top of a short hill Bull spooked. My friend encouraged him to move forward but still he balked. 
Jeanne Mitman was surprised when her normally steady mount Bull repeatedly balked at going up a familiar trail. Mary Phelps
Not wanting to have an accident with either horse we turned off the path into a field of corn stubble. Once away from the hill Bull settled down and his normal demeanor returned He was once again a steady but alert trail horse. But I had no clue to what had set him off. So although my green horse had handled the ride satisfactorily I knew I would need a session with the older horse.
The next weekend I headed out alone on Bull along the same route. Again at the top of the hill he spooked and spun. Bull and I had handled these situations before so I kept him pointed forward and tapped him with my whip. He took a few tentative steps. I still could not detect the source of Bulls anxiety but I suspected he was reacting to the scent of a decaying carcass. 
A shocking discovery
Slowly haltingly we approached the section where the path crossed under hightension wires attached to large utility towers. Then I heard it a definite hum or buzz from above! 
I looked up and saw one of the wires