White-tailed Deer doe and her young fawn in the southern most part of The Colony, Texas.
Here is what Wikipedia has to say about White-tailed Deer:
The white-tailed deer is a ruminant, which means it has a four-chambered stomach. Each chamber has a different and specific function that allows the deer to quickly eat a variety of different food, digesting it at a later time in a safe area of cover. The Whitetail stomach hosts a complex set of bacteria that change as the deer’s diet changes through the seasons. If the bacteria necessary for digestion of a particular food (e.g., hay) are absent it will not be digested.