|plastic bottle, tape, a straw (cut to size), stickers and plastic craft lacing.|
Tape the straw to the top of the bottle then decorate the bottle with any kind of stickers. The Kiwi Crate had 1x1 inch square transparent stickers but we just used animal stickers that Busy picked from the 1 million sticker books that we have. String the lacing through the straw and tie both ends to something sturdy. We tied ours to the window lock and taped the other end to the top of the TV stand. Just make sure that one end it higher than the other so when you let go of the bottle, it will move. Busy played with the zip line for a good 20 minutes, taking the taped end and placing it on various surfaces at different height levels to experiment. To make it more interesting, or for older kids, you could also use yarn and other materials as the line to experiment with friction.