Why do cats eat grass? It's one of the most common questions that any cat owner has. And to answer this question, you need to understand the feline digestive system.

Unlike humans, cats are carnivores, which means the natural diet for a cat is meat.
However, cats will eat grass when they can't stomach their food properly or if they have a condition such as hairballs. Grass helps remove any hair that's been swallowed and in the process aids in digestion.
There are some instances where a cat will eat grass due to an upset stomach or as a way of vomiting after eating something toxic. In these cases, it is important for your cat to vomit up the foreign object rather than try to digest it over time. But sometimes, the reason why cats eat grass is because they're not getting enough nutrition from their food or water sources. In these cases, you should visit your veterinarian to see what's going on.