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A catnipped cat is a sight to behold. They lick and chew the wondrous herb, rub their faces in it, and roll around on the ground. Sometimes they drool or run screaming through the house. Some cats, on the other hand, don’t seem to care for catnip at all. Cats are truly a never-ending source of entertainment and mystery. Scientists of many stripes have been investigating the relationship between cats and catnip since at least the 1960s, so many questions have been answered, although some still remain.
Catnip, also called catmint or catwort, usually refers to the species Nepeta cataria, but can include any of the 250 or so species in the genus Nepeta. Cats react to quite a few of these species, not only Nepeta cataria, the most well-known catnip. Catnips are members of the mint family. Most of the species are perennials. They have opposite leaves, grey-green foliage, and small flowers in a variety of colors. N. cataria has pink or white flowers. Catnip is aromatic even to humans, smelling minty and perhaps lemony. It is the scent of catnip that attracts felines to the plant so strongly.
Not all cats care for catnip, but it does seem to be the case that all species of cats have the catnip reaction, or at least a lot of them. Wild cats large and small have been observed reacting to catnip in the same way that domestic cats do, although just like housecats, not all of their wild brethren are fond of the stuff, either. The chemical in catnip that causes this more-or-less universal reaction is nepetalactone, a volatile oil produced in glands on the underside of the leaves (1). Nepetalactone repels insects, so it is thought that the plant produces the oil in order to repel herbivorous bugs (2), but the chemical appears to mimic a natural cat pheremone. At least, that’s the theory, given that the behaviors exhibited during the catnip reaction bear a striking resemblance to some of those of a she-cat in heat (3).
When a cat inhales nepetalactone, the volatile oil binds sensory receptors which trigger neurons in the olfactory bulb of the brain (4). These neurons, in turn, relate the message to brain regions that cause an emotional and sexual response to the stimulus (4). Catnip is sometimes called an “euphoriant” for cats, although in truth we can only guess at what they are feeling.
Inhaling the scent of catnip is usually stimulating while eating catnip mellows cats out, although individual cats can react to catnip differently. Some may even become aggressive toward other cats or people, so keep an eye on kitty until you know how they are going to behave under the influence, so to speak. The entire reaction lasts about ten minutes, after which the cat cannot react again for up to two hours. Catnip is considered non-addictive and safe. Too much catnip at once can cause a cat to get sick, like anything else. You might want to store your catnip well out of reach if you buy a large amount. Nepetalactone loses potency over time, so it’s a good idea to keep dried catnip in the freezer to avoid this anyway.
What about cats who are indifferent to catnip? There are two possible reasons. First, kittens, with possibly some rare exceptions, do not react to catnip and may even avoid it (5). Cats begin to experience the excitement of catnip around six months of age, when they reach sexual maturity. Interestingly, this occurs even when cats are spayed or neutered (5). But some cats never do become interested in the herb, and this is due to genetics. There is a dominant allele which confers the catnip reaction on cats who inherit at least one copy of it at that gene (5). Anywhere from 20-50% of cats are estimated not to react to catnip and therefore to have two recessive alleles for that trait. What that means for their biology otherwise is hard to say, as the reason for cats reacting as they do remains a matter of speculation.
If you have a cat that likes catnip, you might consider growing a pot of it yourself. Mint species tend to be sprawling and invasive–catnip has already become weedy and invasive outside its native Eurasia and Africa–so I would recommend confining it to a pot. But then you would always have fresh catnip available for your kitty and, for that matter, yourself. Catnip has been used medicinally for hundreds if not thousands of years. In addition to its repute as a natural bug repellent (albeit only for a few hours at a time), it has a mild sedative effect on the human brain similar to chamomile. Herbal teas of catnip may be good for anxiety or insomnia, or just good for relaxing after a hard day.
Native Americans once used catnip to treat infant colic, and the herb is reputed to be good for migraines, digestive complaints, and as a paste for arthritis (4). I cannot personally vouch for these healing properties, but I can say that I kill every plant I try to grow, and even I managed to grow a nice, healthy catnip plant for several months, which is probably a record for me. The cats loved the fresh catnip, but I did have to move the plant outside to prevent them from just munching the whole thing to the dirt. At least I knew they liked it.
Fun fact: other plants, such as valerian and silver vine, affect cats the same way as catnip!
Works Cited
- John Innes Centre. (2018, December 11). How catnip makes the chemical that causes cats to go crazy. ScienceDaily. www.sciencedaily.com/releases/2018/12/181211103125.htm
- Eisner, T. (1964). Catnip: Its raison d’être. Science, 146(3649), 1318-1320. DOI: 10.1126/science.146.3649.1318
- Palen, G.F. and Goddard, G.V. (1966). Catnip and oestrous behaviour in the cat. Animal Behaviour, 14(2-3), 372-377. https://doi.org/10.1016/S0003-3472(66)80100-8
- Turner, R. (2007, May 29). How does catnip work its magic on cats? Scientific American. https://www.scientificamerican.com/article/experts-how-does-catnip-work-on-cats/
- Todd, N.B. (1962). Inheritance of the catnip response in domestic cats. Journal of Heredity, 53(2), 54-56. https://doi.org/10.1093/oxfordjournals.jhered.a107121
Published April 17, 2020
Updated January 30, 2021
