Why not let the chooks do all the hard work improving your soil with this movable chook pen? This chook tractor has an open floor that allows chickens to remove weeds and bugs from patches of ground, leaving their valuable fertiliser behind. Once the chooks have gone over one area you can move them to the next space. Chook tractors are also great for containing free-range chickens at night. The instructions below make a tractor 3 metres in diameter and 1.5 metres high.