I know that students writing their letters in a mirror image is common, yet something you need to watch. Lately I am having a lot of students start to flip letters that have never done it before. The common ones are b/d, p/q and S. When do I need to start worrying about this? They don't realize they are doing it, until I point it out. If I point it out, they correct it. They don't always flip the letters either. This isn't just one student, it's like 4-5 students who are now doing it on a regular basis, but not ALWAYS. I don't want to ignore this.