Gather together paper and crayons to make bark rubbings. Egg crayons work especially well for young children: Simply melt down pieces of crayons and have them harden in egg-shaped molds (available in stores). Then head outside. Have each child hold a piece of paper against the bark of a tree and rub with the side of a crayon. The print of the bark will appear on the paper. In this way, children can "take" the tree back inside with them!