It always surprises me what some people don't know - like the first couple who didn't know that a cat with a twitching tail is "danger, danger!" I remember my dad telling me that when I was maybe 4 years old. (Before I was allergic to kitties, and was enthusiastically petting one of my cousin's cats ...) Thanks to early instruction on paying attention to such signals, I have only been scratched by cats twice - and both times they were serious about wanting to nail me. The first was when I was doing homework over a friend's house, and I dropped my pencil. It rolled under the couch, so I just reached under to snag it - and got nailed! Dawn then said "oops, forgot to tell you - that's where Kitty lives, and if it rolls under there, it's hers!" The second - a longer story for another day ...