A couple of members have posted about transferring their chickens to a daytime tractor and putting them back in the coop at night. One person actually designed their tractor and run for that purpose. They installed guillotine style doors, so the tractor and run could be right up against each other for a smooth transition. They used scratch as a bribe to get the chickens into the tractor. After a day or two, the chickens were eager to get into the tractor, because they liked the fresh grass.