According to the event organizer:
Chicken tractors are a small chicken run without a floor that allow you to safely move your chickens around your yard or garden for the purpose of foraging for bugs, grass, weeds. These are also great for depositing fertilizer (droppings) around your garden. It can also be used to help rid your garden bed of pest by placing the tractor over a garden bed and letting the chickens do what they do best, scratching for bugs.
*This class takes place in the Bronx