Occupied!

“Some areas of your building may not be in use at all times where the lights would be on otherwise (such as hallways). By installing occupancy sensors which turn on when there is movement, you will be able to have lights be on only when the area is needed. No more needing to illuminate that back hallway that is only used a few times a day all of the time!”

https://www.myledlightingguide.com/blog-ways-to-save-energy-at-school