orange tabby cat eating grass
Facebook Pinterest Twitter

Why Do Cats Eat Grass?

Est. read time: 6 min.

Eating grass is another one of those head-scratching habits that some cats partake in that make us wonder, “Why?” Some people think that cats eat grass only when they have an upset stomach, but there’s no single reason why cats sometimes want to supplement their diets by eating grass. While cats are famously carnivores, their digestive systems are adapted to process grass as well. 

In general, your cat eating grass shouldn’t be a concern—unless you treat your yard with products such as herbicides, non-organic fertilizer, or pest control products. Even if the product is advertised as pet-safe, it is best to wait the recommended amount of time of 24 to 48 hours prior to letting your feline wander on a treated lawn. Aside from this specific scenario, if you see your cat eating a lot of grass and vomiting frequently afterward, it is important to seek help from your veterinarian.

Top reasons why cats eat grass

As previously stated, there are many reasons why a cat may eat grass, but continue reading to find out why they most commonly indulge. 

Maine Coon eating grass

Is grass bad for cats? Not necessarily! Cats sometimes eat grass for health benefits or because they like the taste and texture. The most common reasons cats eat grass are:

  • Expelling intestinal parasites
  • Boosting vitamin levels
  • As a laxative to improve digestion
  • Inducing vomiting
  • Helping relieve anxiety or stress
  • To explore

Here’s what you need to know about each of these:

Expelling intestinal parasites 

Researchers previously theorized that cats eat grass based on an instinct to expel intestinal parasites. Much like chimps and other wild animals, it is suspected that your cat’s wild ancestors used grass to expel parasites commonly contracted through eating raw meat. Due to advances in veterinary medicine with a huge emphasis on preventative care, house cats today don’t typically have intestinal parasites (unless they’re doing a little outdoor hunting!)—but the instinct to eat grass clearly remains. 

Boosting vitamin levels 

Grass is high in vitamins and trace nutrients. Your cat might be eating grass to boost their vitamin levels. Grass contains nutrients such as folic acid, which can help move oxygen through the bloodstream. Grass is also high in vitamins A, C, and E, iron, magnesium, calcium, and amino acids, making it a nutrient-dense dietary supplement for your cat.

As a laxative to improve digestion 

Sometimes cats need a little help to move their digestion. When cats hunt and eat small animals like mice and birds, the little bones, fur, or feathers could be eaten, but won’t pass easily through their digestive tract. Grass works as a laxative to move this indigestible material through the digestive tract or possibly vomit up the less digestible parts of their protein-rich meal. 

Inducing vomiting 

In case of severe indigestion, cats may ingest grass in an attempt to help them expel fur and other things like feathers that can’t be digested. Seeing your cat eating grass could be a sign your cat has digestive issues that need further examination by the vet. 

Relieving anxiety or stress 

Sometimes anxious cats eat or chew grass to calm their nerves. If you notice that your cat is chewing on grass excessively, check if they are showing other signs of stress such as aggressive behavior or withdrawal. If so, get in touch with your veterinarian to see how you can help your pet’s anxiety.

To explore

When in doubt, taste is an essential sense that our feline friends use to explore the world. Whether tasting the grass is just scoping out new territory or checking to see if there’s something exciting going on with the environment, cats are extremely inquisitive by nature and will utilize all of their senses to fully experience the world.  

Is it normal for cats to eat grass? 

Yes, it is normal for cats to eat grass. Eating grass and green plants is common for cats. Most pet parents who let their cats go outside will report that their cat eats grass at least occasionally. As long as it is not excessive, there is no reason for concern about cats and grass. But if you treat your lawn with herbicides, non-organic fertilizers, or pest control products (even those that are marketed as pet-safe), you’ll want to prevent your cat from eating any treated grass. 

What to do when your cat eats too much grass

If the grass eating becomes excessive and your cat is vomiting frequently, this can indicate problems with the digestive system. You should contact your veterinarian for help. 

If your cat is a grass eater, you can take some precautions. As mentioned earlier, make sure you are not using herbicides or products on your lawn. Remove any plants from your garden that are toxic to cats

The best idea? Grow cat grass indoors for your cat! With cat grass, you can be sure it’s safe to eat. Cat grass seeds are available at most pet stores. Many cat grass seed packets will contain a mix of wheat, oat, barley, and rye seeds. You can also grow wheatgrass, oat grass, barley grass, and rye grass individually.

Trust your cat’s instincts 

So, why do cats eat grass? While it seems like strange behavior, eating grass is normal and generally safe for cats. From better digestion to boosting vitamins, cats have a natural instinct for how to build their health. If they go outside, that often involves grass. To help support your cat’s health, feed them a regular, nutritious diet. Feeder-Robot, an automatic cat feeder, can help your cat maintain healthy eating habits. Additionally, a self-cleaning litter box like Litter-Robot can help you monitor your cat’s waste habits and be aware of digestive problems.


Do only sick cats eat grass?

No. Some cats eat grass because it is a basic instinct to do so, or they like the taste.

Can cats digest grass?

Cats lack the enzymes necessary to digest grass. That's why they sometimes vomit after eating it, or why grass can have a laxative effect.

Do cats eat grass when they have worms?

Sometimes, yes, cats will eat grass to get rid of worms and other parasites.

Do cats eat grass to throw up?

In the case of indigestion, some cats will eat grass to throw up hair or feathers stuck in their digestive systems.


tabby cat lying in the grass with tongue out - why do cats eat grass?