Peek into your backyard and your art-supply drawer -- odds are you have everything you need to make this bat mobile.
Trace our bat templates onto black card stock; cut them out and fold them according to template instructions. Make a small hole in the center of each bat with a tack. Poke a piece of thread through each hole, and knot it. Tie the bats to a found branch (painting it black is optional). Then hang the branch from two pieces of thread secured to the top of the window with flat thumbtacks.