Cats do a lot of strange things. They follow us to the bathroom. They run down the halls at 4 am when the rest of the house is sleeping. They lick plastic bags. And some cats eat grass (or plants), when they ought to be perfectly obligate carnivores.
It's always been a bit of mystery as to why exactly cats go after greenery. Most theories suggest that cats nibble on the lawns when their stomachs are upset as a way to help them toss their kibbles, so to speak, or get rid of hairballs. Other theories suggest that plant-nibbling is a learned behavior, passed down by their mothers or older cats in the household.
A recent study suggests that eating greens is actually an evolutionary behavior, one that isn't a 'learned' behavior and an instinct that isn't directly intended to provoke vomiting. Instead, cats are instinctively motivated to chomp down on grass because it's how their wild ancestors got rid of internal parasites.
The process of digesting tough, fibrous grass increases muscle activity in the digestive tract, which can be useful in expelling nasty hookworms and roundworms. The theory is based on research in chimps and other wild animals. While most of today's indoor cats don't suffer from internal parasites, the authors argue that this instinct strategy developed in a distant ancestor.
The survey of 1000 cat owners on the Internet who spent at least 3 hours a day watching and hanging out with their pet concluded that Seventy-one percent of the animals were caught in the act at least six times in their lifetime, whereas only 11% were never observed gobbling greenery.
If you have a cat that likes to nibble, consider planting them a cat grass garden of barley grass, which can often be bought at local supermarkets or pet stores.
You should also be sure to decorate your home with cat-friendly houseplants if your cat's a nibbler - a lot of common household plants can actually be dangerous to felines if ingested.
[h/t: Sciencemag ]