We all know the typical things that dogs react adversely to . . . vacuum, people/dogs on other side of fence, trucks/buses/trains, doorbells, sirens, thunder, coyotes . . . What really strange things unhinge your dog? Melli -- anything that makes the pssss pssss pssss sound -- husband's airbrush or tonight cutting foam insulation with a knife. Makes me wonder if her former home was a Spanish-speaking (we know that part) chop shop! Or did they hit her with canned air? Shay -- the stimulation segments on Dog TV. Have to change channels! He also fears my husband's wire gun (kind of a nail gun) because he knows it makes the compressor kick on.