Just make a single wheel woodpecker. Piece of sheet metal cut roughly to a circle, drill/punch a hole through the center, put a bolt through the hole and attach it to a handle of some sort, then cut some teeth in to it with some tin snips, a dremel cut-off wheel, etc. Wanna get fancy, build a few wheels and put washers between them and you'll have a woodpecker for 1/50'th the price.