A cat can spend most of the day looking mildly disappointed in everyone around it. Then you offer a little dried plant, and suddenly it is rolling on the floor with a stuffed banana.
What exactly happened?
Catnip contains a chemical called nepetalactone. Its smell can trigger the familiar combination of rubbing, rolling, licking, and general silliness. But not every cat joins in. In a 2017 study of 100 domestic cats, about two-thirds responded to catnip. Almost 80 percent responded to silver vine, another plant that can produce similar behavior. A cat that ignores catnip is not missing a personality. It may simply prefer a different smell.
Silver vine has helped scientists understand what happens during these episodes. In a 2021 study, researchers identified a compound called nepetalactol that triggered the response. Exposure increased the cats’ levels of beta-endorphin, one of the body’s own chemicals involved in reward. Blocking the relevant receptors reduced the rubbing behavior. That gives us a biological reason to think the experience is rewarding, although we cannot ask cats exactly how it feels.
The rolling may also accomplish something useful.
The researchers found that rubbing against silver vine transferred the active compound onto the cats’ heads and faces. Under experimental conditions, that helped repel mosquitoes. The cats were effectively applying a plant chemical to their fur while doing something they appeared to enjoy. This is an interesting biological finding, not a reason to replace veterinary parasite prevention with catnip.
A follow-up study published in 2022 looked at another part of the performance: chewing and crushing the leaves. Damaging the leaves increased the release of the relevant chemicals. In silver vine, it also changed the mixture of compounds, making the resulting blend more effective at repelling mosquitoes.
That does not mean your cat has identified a mosquito problem and developed a treatment plan. An animal can benefit from a behavior without understanding its chemistry.
I like this example because the behavior is so easy to dismiss as random. Watch a cat wriggle around on a toy, and the obvious explanation is that the cat has temporarily become ridiculous.
There is nothing wrong with enjoying that explanation. But underneath the performance are specific plant chemicals, a measurable biological response, and possibly a useful function.
The herb-filled banana is doing more interesting work than its appearance suggests.
Ezra Ameis, DVM
Paw Priority, Los Angeles