Deer are vegetarians, and they feed mostly on plants. Deer eat different things depending on what season it is. In spring deer eat mostly grasses, flowers, buds, and young leaves. In the summer when those foods dry up they eat twigs, stems, and mature leaves. In winter deer will eat twigs and small tree branches. If food becomes extremely scarce deer will eat bark. Deer do not chew their food well before eating it. Unlike most animals deer have four stomach chambers. One is a storage place witch let's them eat large amounts of food quickly, so deer do not need to spend long amounts of time at feeding grounds. Then deer go back to a safe place. The stored food returns to the mouth in a ball. The deer chews the ball called cud, then the cud goes to other parts of the stomach. Animals that chew there food in this way are called ruminants