Are you a leg-jiggler, doodler, hair twiddler or pen clicker? If so, you're not alone - many of us are fidgeters.
These habits are often seen as a mark of boredom, and viewed negatively, but there's growing evidence that fidgeting can actually aid focus.
Dr Kat Arney is a science writer and broadcaster who has interviewed academics, neuroscientists and fidgeters for her BBC podcast Fidget On Four.
Her previous books include Herding Hemingway's Cats: Understanding How Our Genes Work (2016) and How to Code a Human (2017). Her latest book Rebel Cell, about the evolution of cancer, is due out in August.