Why does a horse stand in a storm?

Well, after a delay due to technical difficulties (let us call it that instead of operator error!)... I would like to post my friend Susan McCarthy's response to the much asked question... why do horses often stand out in a raging storm instead of seeking shelter?

SUSAN's RESPONSE:
Aw gee, Kristi, no fair. How would I dare pronounce on a subject that baffles all those horse folk?

I will say that standing out in the open doesn't protect a horse from lightning, although it should protect it from falling trees and tree parts.

I will also speculate that when weather is bad, horses will do what their wild ancestors did in bad weather. And what that would have been (I continue to speculate) would have been to go to a pasture in the lee of a hill if possible and if not possible and in any case, to orient themselves to the wind and wait it out. Not to go looking for a warm dry well-bedded stall....

I would make an analogy with llamas, who live in open alpine areas, and who apparently do not understand the concept of shade. Where they are from there is no shade and perhaps they never need shade. So when some llamas were being held in quarantine in Antigua and were suffering horribly from the heat and sun, it never occurred to them to get into shade. People had to chase them into the shade.

http://www.nytimes.com/1989/04/23/world/failed-plan-leaves-llamas-dying-in-tropics.html?pagewanted=all

So that's the best I can do: maybe the horse instruction manual simply doesn't include the warm dry stall option....
Failed Plan Leaves Llamas Dying in Tropics - NYTimes.com
www.nytimes.com
LEAD: Thousands of miles from their home in the cool mountains of South America, a herd of woolly llamas and alpacas have been stranded on a Caribbean island and are slowly dying from heat and stress in the broiling sun.