Your beloved canine companion clearly isn’t a cow, so you might be confused when you see him eating grass. You might even be worried. Is he hungry? Bored? Sick? Will eating grass hurt him?

First, rest assured that you’re not alone in your concern, especially if your dog is eating grass and vomiting.

Pica is the technical term for the disorder characterized by eating things that aren’t food. Sometimes pica indicates that your dog has some type of nutritional deficiency, though it is often simply a sign of boredom, especially when practiced by puppies and younger dogs.

Dogs eating grass is actually quite common (it has been observed in wild dogs, too, and may be completely natural) and this form of pica does not usually cause too many problems. In fact, most veterinarians consider it a normal dog behavior. One small-scale study of 49 dog owners whose dogs had regular access to grass and other plants found that 79% of the dogs had eaten plants at some time. Another survey about plant-eating dogs found that grass was the most commonly eaten plant.