Many behavior reports for Preschool include students’ difficulties in sitting still. There is a reason for this; Young children are not meant to sit still for long. In fact, research finds movement improves learning results.
In my class, we practice flexible seating. Students are free to exercise choice if and where they sit. My clear expectation is that they pay attention to the lesson or are engaged in an activity. Students are responsible to manage their own seating. My main lessons occur on a large rug. Seating options include large pillows which children may situate wherever and next to whoever they may wish.
Sometimes students will chose to lie down. They may choose to sit on a shelf or table for a better vantage. For very active children, a teacher may also find students prefer to be standing or even running! This may be distracting at first, just remember the expectation they are paying attention and are engaged. Then assess if any redirection is truly necessary. Empowering children to choose where and how to situate their own bodies prevents classic behavior issues, teaches them self-management, and improves learning.