The Mule deer have an interesting digestive system. They are ruminants like cows which means they have four stomachs. When a deer eats they eat quickly, only chew food good enough to swallow it. The Rumen is a storage for food and holds lots of food. The deer then can allow the food to come back up into the mouth which is called chewing cud. The second stomach is the reticulum, this is where the micro organisms stay and they help digest and break down the food which is called fermentation. They then chew cud again this time with micro organisms which then breaks down the food even more. The omasum is the third chamber which absorbs water. The fourth chamber is called the abomasum, the gastric juices break down the food to its finest course so when it goes to the intestines it can be absorbed and the deer gets the nutrients it needs. They prefer to eat more trees and shrubs throughout the year then forbs, grass or grass like forages.