Animal excrement, also known as DUNG, is the waste material produced by animals. It is usually composed of undigested food, bacteria, and other materials that have been passed through the digestive system of the animal. DUNG is a common term used to refer to the excrement of mammals, such as cows, horses, and sheep. It is also used to refer to the excrement of other animals, such as birds, reptiles, and amphibians.