When we think of cats, we picture hunters: sharp eyes, silent paws, a strong preference for whatever is in the fridge. So it surprises many people to see a cat chewing on grass, often with real enthusiasm. Why would a meat-loving animal bother with greens? Scientists have been asking that question for decades, and the answers so far are interesting, honest and incomplete. Some studies watched kittens learn new foods. Some asked more than a thousand owners what their cats do. Some looked inside the stomachs of stray cats, and some peered at hairballs under a microscope. Here is a short history of the science of cats and plants, with what it shows and where it stops.
Before we start, a word on what researchers can and can't see. An owner can watch a cat bite a plant without knowing how much it swallowed. Finding leaves in a cat's stomach confirms that it ate them, but not why. And showing a benefit needs a fair comparison, which is much harder to run.
That's why this history has a few twists. Over the years, the evidence has stacked up that plant eating is common and natural for many cats. What it does for them is less settled. Our own review of the published research found no controlled study isolating the effect of giving cats fresh cereal grass, so any effect has yet to be measured properly. With that in mind, let's go back to the start.
1980: Kittens Follow Their Mother's Lead
Our story begins with kittens. In 1980, researchers Wyrwicka and Long gave 19 weanling kittens from four litters daily chances to try a new food. When their mother was eating it beside them, the kittens started eating it after an average of 0.2 days. Without her, the average was 4.8 days. The food wasn't grass, and the study was small, so it can't tell us how cats learn to nibble greens. But it hints at something many multi-cat homes notice: company can make a new food less strange.
It also suggests that a slow start isn't the end of the story. A kitten who ignores something on day one may try it on day five.
1991: Why New Foods Can Take Time
A decade later, a review by Bradshaw described how adult cats can be wary of unfamiliar food, a habit called food neophobia. Tasting a flavor, rather than just smelling it, appeared to soften that wariness. The review also described the opposite: cats can learn to avoid a food for a long time after a bad experience. Together these studies support giving a cat a fair, patient chance with something new.
They don't tell us how long that chance should be, or that every cat will come round. Some cats simply aren't grass cats, and that's fine.
1999 and 2007: Grass Enters the Advice
By the late 1990s, grass had found its way into professional care advice. A 1999 review of how cats should be housed at home, in catteries and in shelters suggested offering grass to cats that like chewing. In 2007, a welfare code in Australia's Capital Territory went further, recommending grass twice weekly for cats whose owners have no garden.
That is official husbandry advice for a specific situation, based on experience and judgment. It doesn't come with an experiment showing the ideal amount, schedule or grass. Later guidance, including a 2010 clinical review and UK charity Cats Protection, also describes grass as something to offer and lets the cat decide.
Wild Cats and City Strays
Meanwhile, researchers looked further afield. A large synthesis gathered 316 records from 213 studies covering 24 wild cat species and found plant remains in their droppings and stomachs. In Perth, Australia, a study of stray cats collected mainly in 2016 found fresh green grass in the stomachs of many of them. And a Japanese study of snow leopards looked for a link between the plants they ate and the hair they passed, and couldn't find a clear one. Theories about why cats eat plants, from helping hair along to an inherited habit, remain hypotheses, not proof. More on wild cats and greens.
2021: The Big Owner Survey
In 2021, Hart and colleagues published owner surveys run in 2006 and 2016. In the second, 725 of 1,021 cats had been seen eating plants at least six times, while 112 had never been seen doing so.
Only a small share of owners, about 6% to 9% across the surveys, reported that their cat seemed ill before eating plants. Most plant-eating cats looked healthy at the time. Owners did report that some cats often brought plants back up afterwards: 37% in one survey, 27% in the other.
Plant eating was also reported at similar rates in long-haired and short-haired cats, which makes a simple hair-only explanation less likely. The surveys are a selected sample, though, not the whole cat world.
2025: Hairballs Under the Microscope
In 2025, Bensel and colleagues looked at six hairballs brought up by two cats under an electron microscope. They found cat hair tangled in the tiny hairs and edges of plant leaves. It's a small study with no comparison group, but it supports a simple idea: grass and hair can travel together. That is the basis for our line that fresh cat grass helps with hairballs. It doesn't show fewer hairballs, and we don't claim it does.
The same year, a UK survey published by Taylor and colleagues found that 84 of 565 caregivers, 14.9%, offered their cats cat grass. So the science so far says plant eating is common, grass is widely recommended as an option, and the rest is still being studied. Our take: offer it, watch your cat, and let them decide.
What comes next? Plenty of questions are still open. No study has yet compared fresh cereal grasses head to head, or shown which grass cats in general prefer. Our own review of the published research found that a good hairball trial would need cats assessed by vets and careful records kept. Until then, the honest summary is short: plant eating is common, and grass is a widely offered option.
A Growing Tradition
From wild cats eating plants, recorded across 24 species, to indoor cats with a box by the window, plants have long had a place in cat life. The science is still catching up, and we're happy to say so plainly. What we can say is that all three of our grasses help with hairballs, and that a fresh box gives your cat something green and safe of their own.
