If your cat turns from an elegant hunter into a drooling ball of fluff at the merest whiff of catnip then you might be curious to know how such a nondescript plant has the power to cripple such a ferocious beast. Seventy per cent of domestic cats are susceptible to catnip, and so are big cats such as lions, but how did this plant evolve to hold such sway over our pets, and what exactly is it doing to them? This week, Science with Sam explains why cats love catnip.
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Cats are fearsome predators. Fast, stealthy, ruthless
Why aren’t you stalking your prey like an assassin? Stay focused! Oh no. This cat is broken. What’s done this to you? A herb?!
Why does this nondescript plant drive this ferocious carnivore crazy? Are you high? I need some answers.
Catnip comes from the plant Nepeta cataria, a herbaceous member of the mint family native to Europe and Asia. When cats get a whiff of it, they seem compelled to sniff, lick and chew its flowers and leaves, rub their faces and bodies on the plant, roll around, shake their heads and drool.
Not all cats are affected, though. Kittens are immune to its allure and thanks to a genetic variation, 7 out of 10 adult cats find it irresistible, but the rest aren’t really bothered. See.
The chemical responsible for messing with cats’ heads is called nepetalactone. It produces its effect through smell alone: the molecule doesn’t have to be ingested or reach the brain for it to send cats wild.
This frenzy of excitement usually lasts around 15 minutes. After that, they become immune to its effects for around an hour.
It might look like the cats are getting stoned, or having some kind of drug trip.
We can’t actually tell what the cats are experiencing, but we do know that smelling catnip triggers the release of beta-endorphins, natural opioid chemicals produced in the body.
In humans, endorphins lower stress, inhibit pain and make us feel rewarded. When these opioid receptors are blocked, cats don’t respond to catnip in the same way indicating that these endorphins are responsible for the cats’ strange behaviour. Plus, they don’t seem to get addicted or suffer any ill effects from the herb.
Any humans looking for a high by smoking catnip may be disappointed. Some people do enjoy a brew of catnip tea, and advocate it as a mild sedative or a herbal medicine, but there are no reliable studies documenting psychoactive effects in humans.
It’s not just our domestic felines that are sent into a frenzy by catnip. Many big cats – including lions, leopards and jaguars all seem to be affected in the same way. Here are some videos from Carol Baskin at Big Cat Rescue showing how her animals respond to catnip. Just like our pets, they too seem to become ludicrously playful. So what’s in it for the plant?
Well, its effects on cats seem to be an evolutionary accident. The plant doesn’t grow in the same areas where these cats live in the wild.
But there is another animal for whom nepetalactone is a sex pheromone: aphids. Aphids like to suck the sap of catnip plants. By producing the pheromone, the plant attracts aphid predators such as the lacewing fly. So it’s actually an ingenious way to protect itself against sap-sucking herbivores.
However, its accidental effect on cats has paid off for the plant in some ways: humans now grow acres of the stuff just for the purpose of amusing their pets.
Catnip has other surprising uses too. Mosquitoes, flies and cockroaches find its smell aversive, so people have used catnip as an insect repellent. It may be that this is why cats have evolved the urge to rub themselves on the plant.
Mice also produce similar molecules, called lactones, in their sweat. According to cat behaviour expert, Benjamin Hart, they might have evolved to do this to distract cats when they get caught, giving it a chance to escape. Maybe this explains why cats often bat around and play with mice, just as they do with a toy mouse stuffed with catnip.
Does your cat go nuts for Nepeta cataria? Let us know in the comments. And if you found this video as irresistible as catnip, click like and subscribe, and sign up for notifications so you’ll find out when our next video comes out.
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