Herbivores are animals that eat only plants. These animals range in size from insects to elephants, and also included some dinosaurs. Many herbivores have bodies that have adapted in order to help them retrieve and eat the food they need. Two examples are the giraffe, whose long neck helps them facilitate the retrieval of food from the tops of trees, and some mammals who have large molars that assist in grinding the leaves and grasses. Some herbivores don’t eat the entire plant, but only eat certain parts. For instance, caterpillars only eat the leaves of plants, and honeybees only eat the nectar and pollen.
One group of herbivores, called ruminants, have stomachs that contain more than one chamber, and are unable to digest plant material directly. Once they chew and swallow the food, it goes to the first chamber to soften and be broken down by bacteria. The animal then regurgitates the food (now called cud, or partially digested food) and once again chews it, further breaking down the material. After swallowing the plant material, the food then moves into the second chamber, where it is further digested, before moving on to the third chamber. The digested food then moves to the fourth and final chamber.