This has two propellers. One propeller for the Mother bird to move up and down like she is feeding the baby birds the worm. One propeller for the baby birds to make them move up and down like they are begging for the worm. Original design animated outdoor wind driven yard art. Made with high quality wood, waterproof glue and automotive paint. All metal parts are brass or stainless steel. Moving parts turn in bushings that are made to run under water.