This is one of the three chickens we have in our back garden. This one can fly a bit so has escaped the current design of our chicken pen a couple of times but, this morning, all three managed to get out. The “gate” is part of the fence latched onto a couple of screws in a wall by twists of wire and I think they are getting looser.
Fortunately, chickens have quite a strong homing instinct so it was not too difficult to leave the gap wide open and herd them back in before shutting up again. We will have to sort it out soon though, both to keep the chickens in and, more importantly, to keep winter-hungry predators out.