Cat owners—and the kitty-obsessed internet—have observed felines go into a frenzy after rubbing and rolling against catnip, Nepeta cataria, when it is nearby. New research published this week in the journal Science Advances suggests that cats not only use catnip for a high but may also use it as protection against mosquitos.
Catnip and a plant called silver vine, Actinidia polygama, are not closely related, but both make cats go wild. The two plants also contain iridoids, which are chemical compounds that protect the plants against sap-sucking insects, reports Sofia Moutinho for Science. After testing catnip and silver vine leaves for potent chemicals that give cats a bit of a buzz, biochemist Masao Miyazaki from Iwate University in Japan and his colleagues identified the silver vine iridoid, nepetalactol, as the key to the feline’s euphoric state and protection against mosquito bites.
Miyazaki and his team presented a menagerie of cats ranging from big cats at the zoo to domestic and feral cats with scraps of paper soaked in nepetalactol. No matter how big or small the cats were, the results were the same: All cats began to anoint themselves with the paper, reports Katherine J. Wu for the New York Times.
After observing the cats in ecstasy, Miyazaki and his colleagues were sure there had to be more benefits to this behavior besides the intoxicating experience. Previous studies have shown that catnip releases an iridoid called nepetalactone that is ten times more effective at repelling mosquitos than DEET. Taking a cue from past research, the team tested how well silver vine-derived nepralactol protected the felines against mosquitoes. Cats covered in nepetalactol attracted significantly fewer mosquitos——in some cases, by half as many—than cats left untreated with the chemical, reports George Dvorsky for Gizmodo.
“This is convincing evidence that the characteristic rubbing and rolling response functions to transfer plant chemicals that provide mosquito repellency to cats,” the researchers write in the study.
Cats’ attraction to iridoids has puzzled researchers for years, and experts still are unsure why the chemical affects cats but does not affect other animals like dogs or mice, reports the New York Times. The researchers involved in this study argue that this behavior evolved in cats to aid them when stealthily stalking prey.
“Anyone who has ever sat in the field to observe animals ambushing prey knows just how difficult it is for them to keep still when there are many biting mosquitoes around," Miyazaki tells Science.
Mikel Delgado, a cat behaviorist at the University of California Davis, who was not involved in the study, says that this behavior could have also evolved to protect felines from mosquito-borne diseases like heartworm, reports the New York Times.
The researchers are currently looking into how nepetalactol could be used as an insect repellent for humans and have already submitted a patent, reports Science.