For those of you who have no idea what a chicken tractor is...."A chicken tractor is a movable floorless chicken coop for the purposes of pest control, lawn care, fertilization, and sheltering the chickens. When compared to traditional chicken coops the chicken tractor is far superior in many ways. The chicken tractor is a large step towards sustainable farming, and solves many of the problems that are presented by traditional coops and buildings used to house chickens." (according to uoregon.edu).I went with my own design but it is based mostly on a tractor by James Satterfield. I haven't seen it in person but the picture on his site gives a good idea of how it works. You can see it at his website.