I don't know about ridiculous, as I think their reaction is within reason, but my three boys hate motorcycles; specifically those with loud pipes. I live on Main St. which has a corridor of brick buildings on both sides (including the one we live in) and the cyclists love to accelerate down the hill which creates a hell of a noise. This happens daily and all three cats jump every time; you'd think after all these years they'd be used to it by now.