Physical data visualizations tap into our lifelong experience of perceiving and manipulating the physical world, either alone or with other people. However, most physical visualizations are either monolithic and static, or require human intervention to be rearranged. We drew inspiration from existing physical interactive systems and data storytelling practices with physical tokens (like those of the influential Swedish professor Hans Rosling) to develop Zooids, tiny wheeled robots that can move rapidly on any horizontal surface. We used Zooids to explore physical data visualizations that can (1) be manipulated by humans, and (2) update themselves through computerized mechanisms.