A poultry pen, also known as a COOP (4 letters) or hencoop (7 letters), is an enclosed area used to house chickens, ducks, and other types of poultry. It is typically made of wood or wire mesh and provides protection from predators and the elements. The pen also provides a safe place for the birds to lay eggs and roost. It is important to keep the pen clean and well-ventilated to ensure the health and safety of the birds.