...my tb mare can be standing over the top of a sprinkler when it goes off (auto sprinkler) and she'll startle a tad, jump to the side and continue eating. My wb gelding on the other hand jumps, snorts, kicks and farts if he is in the same position. It takes him a while to settle. Same situation yet two different reactions. One is acceptable and one isnt but it shows that a horse doesnt have to lose his mind to deal with a 'trigger'.