Here& an arts and crafts activity for preschoolers and pre-kindergarteners: build brick buildings with homemade mud bricks made from dirt and water.
How (and why) to make stick people dolls from sticks, fabric scraps, wool & googly eyes.
The Imagination Tree: Hedgehog Hibernation Exploration Basket
Making a Nature’s Brew – Nature and Water Play for Toddlers
Super fun tree identification project for kids! Includes free printable tree tags & leaf/seed identification sheets too! - Use "specimen jars" and ask the question "what is it?