Chewed and Rolled: How Cats Make the Most of Their Catnip High

Cats are a mystery to those that know them well. They sleep a lot. Why do they want you to pay attention only for a short time? How can they get back to their home after being away for so long? The writer Haruki Murakami, who is known for putting cats in his novels and essays, once confessed to not knowing why he does so.

Cats love catnip. Most domestic cats will lick it, rub against it, chew it and roll around in it if they are exposed to it. They get high off it. Silver vine, a plant that is not related to catnip but elicits the same response from felines, is one of the plants they go wild for.

This behavior was a mystery for a long time. The bug repelling effect of iridoids, the chemicals in the plants that induce the high, may explain the reaction to catnip and silver vine.

When a plant is damaged by cats, the amount of iridoids released by the plant increases by more than 2000 percent. It is possible that kitty's high confers an evolutionary advantage.

A cat behavior expert who was not associated with the research said that the study built on previous work. A study published last year found that cats would try to coat themselves in DEET-like iridoids by rolling on the chemicals or by rising up to nuzzle them. There could be a benefit to placing compounds on the cat's body.

Carlo Siracusa is an animal behaviorist at the University of Pennsylvania. He said that the evidence showed that they wanted to make their body smell better. A lot of cats don't show this behavior Why would they have been selected like that?

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Bug-repellent iridoids do more to protect plants from insects than to help cats avoid bug bites. Plants emit chemicals that communicate danger to their neighbors when they are damaged, as well as releasing irritant when damaged. Marco Gallio, who was not associated with the new study, said that plants are masters of chemical warfare.

A year ago, Dr. Gallio and his colleagues published a report that linked nepetalactone, the primary bug spray, to irritation in mosquitoes. Thereceptor can be set off by tear gas. Although nepetalactone did not have a negative effect on humans, it did have a positive effect on insects and cats.

The chemical composition of the air immediately above the leaves of the silver vine was measured by Dr. Miyazaki and his associates. They took the iridoid levels in the leaves. Cats released at least 20 times more nepetalactone than intact leaves did, while damaged silver vine leaves released at least 8 times the amount of similar iridoids than did intact leaves. The cat interactions with silver vine made the bug-repelling cocktail even more potent.

Cats are covered in Pest Begone after rubbing their faces against the plants.

This finding, along with Dr. Miyazaki and his team's previous research, supports the idea that part of the benefit of the kitty catnip craze is to stave off mosquitoes and flies. Self-anointing is not the first type of behavior in the animal kingdom. Mexican spider monkeys have been known to use different kinds of leaves to make themselves look like they are in a different place.

There are many questions left to be answered, including why cats only respond to catnip and silver vine, and why some cats do so. Dr. Gallio offered a cautious approach. He asked what he knew. I wasn't there to watch evolution.