One of the most important adaptations that an animal must have in order to eat grass is a large, multi-chambered stomach. This type of stomach allows the animal to store and ferment the grass, which helps to break down the plant material and release the nutrients that it contains.
Another important adaptation that an animal must have in order to eat grass is a set of strong teeth. These teeth are used to cut the grass and grind it down into a pulp, which makes it easier for the animal to digest.
In addition to these two adaptations, an animal that eats grass must also have a long digestive tract. This allows the animal to absorb as much of the nutrients from the grass as possible.
There are many different types of animals that eat grass, including cows, horses, sheep, goats, deer, and rabbits. These animals all have specialized digestive systems that allow them to get the nutrients they need from this tough plant material.