Watch the wind take a spin through your backyard with a homemade whirligig.
Remove the label from the bottle. This is easier if you fill the bottle with hot water and let it sit for ten minutes. Then use soapy water and a vegetable scrubber to remove any residual glue. Drain the bottle and let it dry.
Come up with a decorative image to paint on the bottle and then to make a template by drawing the design on paper. If you choose a symmetrical image, such as a butterfly or flower, draw a straight line down the center of the drawing and then cut out one half of the image. If it's an animal, like a horse or dog, draw a profile of its head and neck.
Tape the template onto the inverted bottle and use the marker to trace around its outer edge (do not trace the centerline or the base of the neck). Repeat this step a few times, keeping an equal amount of space between the outlines.
Use the craft knife to cut along the outlines (adults only). Fold the silhouettes forward at a 90-degree angle from the bottle. Now paint the images.
Once the paint dries, drill a small hole in the center of the bottle bottom. Then insert the dowel into the bottle. Tap the nail through the hole in the bottle and into the top of the dowel so that the head extends one quarter inch above the plastic. Set the dowel in the ground, and the whirligig is ready to catch a breeze.