Once the sun goes down, take preschool children outside to look for stars. Ask children to look for shapes or pictures in the stars. You may also be able to find drawings or pictures of common constellations that children can identify in the sky. Spread out a blanket on a deck or in the yard so children can lay down as they gaze at the stars. Once you go inside, pass out black or blue construction paper and white crayons. Ask children to draw a sky full of stars.
Even preschoolers who are scared of the dark can enjoy flashlight games. Play outside after dark or turn the lights off in a classroom and pretend it's night. If you're playing outside, play in a closed-in yard so children can't get lost. To play flashlight hide and seek, have one person close her eyes. Guide other children into hiding spots using a flashlight. Once everyone's hidden, give the light to the "It" child. When she shines the light on other children, they're out. Children can also use flashlights and their hands to shine shapes onto a wall.
Give children light-colored paper and a variety of crayons. Encourage them to draw pictures of what nighttime looks like outside their homes. Explain that they shouldn't draw a dark night sky, since they'll add that step later. Children must press down fairly hard on their crayons. Once the pictures are done, pass out dark watercolors such as black, purple and dark blue. When children paint over the entire picture, the crayon images will show up against the dark sky.
Teach children about the kinds of insects that come out at night by creating simple traps. Give each child one half of a grapefruit and a spoon. Help children scoop all the flesh out of the grapefruits to leave only rinds. Take children outdoors at night to place their grapefruits on the ground wherever they want. Head inside and ask children to draw pictures of the creatures they expect to find in the morning. The next day, take children outside. They should find a variety of creatures on their grapefruits.