Understanding Catnip Might Help With Mosquito Control

When cats roll in and chew the plant, it releases more pest-repelling compounds

orange cat rolling in catnip
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Most cats go bonkers over catnip.

It’s a distinctive response as they giddily chew and lick the plant, rolling in it, and rubbing their faces in it. Cats act the same around silver vine, an Asian plant with similar properties.

Scientists and pet owners long believed that these plants are intoxicating to felines, but new research finds that may not be the only reason cats enjoy them so much.

A new study from researchers in Japan showed that when cats damage catnip by rolling around in it and chewing on it, the plant releases higher amounts of the compounds that protect them against mosquitoes and other pests. So enjoying the intoxicating plants also have protective properties.

“I am interested in the instinctive behavior of animals, especially companion animals, for example, the behavior elicited by chemicals such as pheromones,” lead author Masao Miyazaki, an animal behavior researcher at Iwate University in Japan, tells Treehugger.

The instinctual response to catnip and silver vine is induced by plant metabolites (substances produced during metabolism), Miyazaki says. Catnip and silver vine leaves contain the compounds nepetalactol and nepetalactone, which protect the plants from pests.

“However, nobody knew why cats respond to these plants and why only felids do the response,” he says. “To answer the questions, we started to study the plant-induced response in cats and other felids.”

Testing Cat Reactions

In past work, Miyazaki and his colleagues discovered the compounds were able to repel Aedes albopictus mosquitoes, which are common in Japan and Chine. This time around they wanted to find if what the cats did to damage the plants helped make them even more effective to chase off pests.

First, to see if the cats were reacting to those specific compounds, researchers offered them Petri dishes of pure nepetalactol and nepetalactone. They found that the cats reacted nearly identically to the compounds as they did to the plants. They would lick the chemicals on the dish and rub and roll all over on the dish.

Then they applied the compounds to the bottom of the dish and topped it with a plastic cover with air vents so they couldn’t reach them. The cats still showed the same licking and chewing behavior even though they couldn’t touch or taste the chemicals. This showed that the behavior around the chemicals is instinctive, Miyazaki says.

“Rubbing and rolling allows cats to transfer nepetalactone and nepetalactol, which also have mosquito repellent activities, to their fur. Thus, the response contributes to chemical pest defense in cats,” Miyazaki says. “This response is one of instinctive behavior. Thus, cats do the response without purposefully, indicating that current cats would not know the effect of the response.”

The results were published in the journal iScience.

Researchers hope the results will help with the formulation of pest control products.

“A most important point is that our research will be of interest to the public,” Miyazaki says. “The other point is that our findings will be useful to develop mosquito repellents that are derived from natural compounds.”

View Article Sources
  1. Uenoyama, Reiko, et al. "Domestic Cat Damage To Plant Leaves Containing Iridoids Enhances Chemical Repellency To Pests.Iscience, 2022, doi:10.1016/j.isci.2022.104455

  2. lead author Masao Miyazaki, an animal behavior researcher at Iwate University in Japan