After viewing the clip, ask the children to find any dark places in the classroom. They might discover shadowy corners, for instance, or spaces under tables and furniture, as well as darker areas, such as cupboards. Ask, "Where else in the classroom do you think is dark?" Children might suggest it is dark inside closed drawers or containers such as tins and boxes. Ask, "Why do you think it is dark in these places?" Establish that dark conditions are caused when light is blocked out. Let pupils explore the dark and shadowy parts of the classroom with torches. Do they notice more detail? More colour?