Pets may eat grass for a variety of reasons, including to soothe an upset stomach, to add fiber to their diet, or simply because they enjoy the taste or texture of grass. It is also believed that some pets may eat grass for nutritional reasons, such as obtaining certain vitamins or minerals that are lacking in their regular diet. However, it is always best to monitor your pet's grass consumption and consult with a veterinarian if you have concerns about their grazing habits.