Sheep in the Italian Alps prefer to eat certain types of plants over others in dry grasslands. They like grasses more than other plants like shrubs or herbs. Some specific grasses, like Bromus erectus and Koeleria vallesiana, are their favorites. When there are more sheep in an area, they eat more of these preferred plants. By controlling how many sheep graze in an area, we can influence which plants they eat, which can change the types of plants that grow there in the long run.