Get tips and tricks from THE EXPERTS for Building and looking after your Chicken Coop. A chicken coop is a building where chickens are kept. Interiors usually have nest boxes for egg laying, and also perches for the birds to sleep on. Coops for meat birds often have neither of these features. There may also be an attached outdoor run, and both the interior and exterior floor of the chicken coop is often covered with a material, such as straw or wood chips, to contain the chicken waste and to allow easier cleanup of the chicken coop. Most have some kind of ventilation to help air out any odors that may occur.