At the beginning of the film where you see all the different failed escapes, there will be one where ginger is hiding in the metal water container and all the other chickens are in the long feeding trough. When Ginger props the gate open with her drinking container, the gate is almost closed (certainly not wide enough to fit the feeding trough through). Next shot the gate is wide open, with Ginger's water container still propping it open. The gate has (very quickly) opened itself!! Surely if the gate could open in this way there would be no problem escaping from Tweedy's Chicken Farm....?