Why Cats Eat Grass & What It Could Mean
By Mawoo Pets Editorial Staff · 5 mins read
Last updated: July 25th, 2025
If you’ve ever caught your cat nibbling on grass in the garden, you may be wondering why. Cats are naturally obligate carnivores, which means they need the nutrients in meat and can’t efficiently digest or get the nutrients they need from plants. Despite this, eating grass is surprisingly common for both indoor and outdoor cats.
So, what’s behind this grass craving? Let’s take a look at what could be driving your cat to eat the green stuff and how you can keep an eye out to make sure your beloved pet isn’t eating anything dangerous.
Is It Normal for My Cat to Eat Grass?
It’s completely normal for your cat to eat grass, whether it’s on the odd occasion or more regularly. Not only do domestic moggies chew on grass, but their wild cousins do too. In fact, many experts believe our domestic felines inherited their grass-eating tendencies from their wild ancestors, although there’s no definite reason accepted by the scientific community as to why cats eat grass.
Your cat may be munching on plants to get extra nutrients such as folic acid and fibre, or they might be eating it to help with their digestive system. Some scientists believe eating grass helps cats digest hairballs better, rather than coughing them up.
When cats eat their prey, they usually eat as much of the animal as possible, including the bones, fur and feathers. Grass may help your beloved companion vomit up what their system can’t digest, or help your cat break them down so they can pass through more easily. If your cat is feeling under the weather and needs to vomit to feel better, they may eat grass to help the process along.
When Grass-Eating Becomes a Red Flag
While eating grass can be beneficial for your cat’s diet and digestive system, it can also indicate there’s an underlying issue.
Some cats vomit after eating grass, but it shouldn’t happen every time. You need to watch out for warning signs such as frequent vomiting, which could indicate your pet has digestive issues, parasites, or even a food allergy. If your cat seems to be obsessively eating grass, it could be a sign that they’re not getting enough nutrients or even that they’re bored and are simply eating grass for something to do.
Another reason why your cat could be eating more grass is because they’re constipated or have an upset stomach, so it’s a good idea to keep an eye on your cat’s bowel movements. Some plants are also incredibly toxic to cats, so make sure to take your pet to the vet if they start drooling, vomiting, or having tremors or seizures after eating a plant.
In the unfortunate event that your cat needs immediate treatment, having a good pet insurance policy will provide a financial safety net for unexpected illness. Many insurers like Petgevity offer cover for pre-existing medical conditions too, along with the standard accident and illness cover. As the unexpected can happen at any time, it’s best to be prepared for the financial implications.
Safe Grass vs. Toxic Plants: Know the Difference
While many cats enjoy chewing on grass, some plants (both indoors and outdoors) can be highly toxic to felines. It’s important to avoid planting toxic plants in your garden and stick to cat-friendly grass such as wheatgrass, oat, rye, or barley grass. Bamboo and lemongrass in small quantities can also be safe for cats.
If your cat is an indoor pet, planting cat-safe grass is a great way to encourage their natural grass-eating instinct while protecting your houseplants from curious nibbles. You can sow cat-safe grass seeds in a shallow pot or container that has drainage holes and place it on a sunny windowsill or a well-lit area, making sure to water it regularly. It’s a good idea to replace the grass every month or so as it wears down or turns yellow, while also trimming it to stop it growing too tall.
To help keep your furry friend safe, it’s important to keep toxic plants away from your pet or ideally out of your house, especially if your kitty is prone to chewing on your houseplants. Lilies are extremely toxic to cats and can cause your cat to become seriously ill or even die. Even pollen or water from a vase with lilies can cause kidney failure in your cat if they eat it, or even skin irritation. Another common houseplant, aloe vera, can cause vomiting, lethargy, and diarrhea in your cat, as can snake plants and spider plants.
If your cat chews on a mystery plant and develops symptoms such as vomiting, drooling or suddenly becomes incredibly tired, you need to take it to the vet as soon as possible, as your cat may need urgent treatment. If possible, take a cutting of the plant in case it will help the vet identify the best treatment for your pet.
Some grass can also contain pesticides and chemicals, which can be harmful to your cat. It’s important you don’t use these harmful chemicals in your garden if you let your cat outside, or at least make sure the grass is covered so your cat can’t eat it.
Should You Let Your Cat Eat Grass Regularly?

It’s instinctual for cats to eat grass occasionally, as it can help aid their digestive system and help hairballs and parts of their prey (such as bones, fur and feathers) pass through. Your cat may also be trying to induce vomiting or ease constipation. But as with any habit, it’s important that your cat only eats grass in moderation. If your cat is excessively eating grass, it could be a sign of an underlying issue with their digestive system or diet, which will need to be addressed.
To help make sure your cat eats the right kind of grass in moderation, you may want to grow your own grass inside, so you can monitor how much they’re eating. If you do so, make sure it’s fresh and free of mould.
Understanding Your Cat’s Grass-Eating Habit
While it may seem odd at first, a cat’s urge to nibble on grass is a natural, instinctive behaviour, and in most cases, it’s nothing to worry about. Whether it’s to help with digestion, manage hairballs, or just indulge their curiosity, cats often enjoy chewing on greens.
Just make sure to monitor how often your cat eats grass and look out for serious symptoms such as vomiting, diarrhea or seizures. If you’re worried that your beloved pet has eaten something they shouldn’t have, contact your vet immediately.
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