Remove and save the caps from acorns. Tape a piece of paper inside a shoebox lid or a foil pan. Have preschoolers roll an acorn in a shallow container of paint. Place the paint-covered acorn on the paper. Move the lid or pan to cause the acorn to roll around, leaving a trail of paint. Repeat the process with different colors of paint until preschoolers are satisfied with their pictures. The children may also dip the open end of an acorn cap into paint and press the circle patterns onto their paintings. Remove the tape and take the paper from the container to dry.
Let preschoolers create a cut-and-paste wreath with paper acorns, oak leaves and perhaps a picture of a squirrel or mouse. Give each child a cardboard pizza or cake base circle. Provide reproduced pictures of oak leaves, acorns and a squirrel or mouse. The pictures can be white or colored, depending on whether you choose to have the kids color their wreath pieces before assembly. Have preschoolers cut out leaves and acorns. They may arrange and glue the paper items near the edges of the cardboard circle. The children may cut, color and glue a picture of a squirrel or mouse in the center of the wreath. Tape or staple a loop of string at the top of the wreath for a hanger.
Give each child an aluminum pie pan. Let the preschoolers help stir up a batch of plaster, or use craft dough that dries easily. Spread the plaster or dough about one inch thick inside the pie pan. Help preschoolers sketch a large capital "A" in the substance. The kids should press real acorns into the plaque along the lines of the letter. Remove the plaque from the pie pan after it is dry, or send it home inside the pie pan to help prevent breaking.
Help preschoolers relate the tiny acorn to the oak tree from which it comes as well as the animals that depend on them for food. Make copies of pictures of oak leaves, acorns, squirrels, mice and perhaps chipmunks. Have the kids cut out and color at least one of each picture. Tape the pictures onto a length of crepe-paper streamer. Fasten the streamer necklace loosely around preschoolers' necks. The children may wear the art project as a belt if they choose.