Yesterday, while home alone and cleaning the basement, I SCREAMED when a dead mouse fell out of a box of junk, as I was taking it down from a shelf. Now, in my defense, I had just observed a different mouse (which had fallen into the basement well window) jump all over the place for something like two hours, pawing all over the window in an apparent desperate attempt to join me. (Yeah, I'm slow, so it took me two hours to realize he wasn't trying to get into the basement but was actually trying to get the heck out of the window well.) So, yes (as a result of a little Facebook poll I conducted), I chose to help him get out and placed a piece of wood into the the well, so that the mouse could climb out.
Shortly after the dead-mouse-in-the-basement incident, I SCREAMED again (and curled my arms into a fetal position (it was quickly pointed out to me), when Kyle appeared out of nowhere in the basement (I had been home alone for hours.) Yes, he enjoyed it very much.
What's your freak-out creature? Mice? Snakes? Roaches? Children?