When cooking eggs, carefully crack and save lower two-thirds of shell intact. Wash and then draw mouth, eyes and nose with a felt tip pen. Fill shells with potting soil. Sprinkle grass seed on surface (ryegrass works well) and gently press seeds into soil. Water gently, put egg shells in egg carton and cover with lid. Keep soil moist but not soggy. The sprouts become "egghead hair" and can be clipped with scissors to keep short or go for the shaggy look.