Why Do Cats Love Catnip So Much?

With instinct and survival acting as the driving force behind the majority of animal behaviours, it’s logical to assume that self-intoxication, as a largely recreational pursuit, would be something limited to the human race.

In reality, however, and often for reasons that mystify biologists, a vast range of species, from insects to fish to mammals, will use and even abuse the wide array of stimulants offered up by nature.

Tree Shrews have been known to consume fermented plant nectar, whilst Bottlenose dolphins hunt and eat Pufferfish and Wallabies partake in poppy pods, all yielding results akin to a 'high'.  Fascinatingly, addiction seems to occur in the animal kingdom at the same rate that it does among humans, perhaps providing some clues to our own dependence on stimulants, from caffeine to narcotics.

The animal most famous for its love of a particular euphoria-inducing plant, however, is found not on idyllic Caribbean shores or within tropical rainforests, but in our own living rooms. The domestic feline is notorious for its love of catnip, reduced to a writhing, purring kitten by just a smattering of the aromatic herb.

But what is it about catnip that produces this effect in cats, and yet not in our canine companions, or even cat owners themselves? The answer lies within the feline’s highly sensitive olfactory system, and its relationship with an organic compound called Nepetalactone.

Nepeta cataria is a species of the genus Nepeta and a member of the mint family commonly known as 'Catnip'. It is a flowering plant widespread throughout Europe, Africa and Asia, with a history of medicinal use – it is known to have a mild calming effect if consumed by humans.

Nepetalactone has been isolated as the isomer in catnip that is so explosively attractive to cats; resembling their natural sex pheromones, the behaviours that it induces are remarkably similar to those of a sexually aroused, or 'in season', cat – vocalising, rolling, head-rubbing. This may explain why cats that are under six months old - not yet sexually mature - are immune to its influences.

Although the exact process isn't yet fully understood, research suggests that Nepetalactone is ingested through the cat’s nose, where it binds with protein receptors that start a chain reaction of signals across sensory neurons, eventually reaching the Olfactory Bulb, central to the processing of smells. From the Olfactory Bulb, the Hypothalamus, responsible for controlling behavioural responses, and the Amygdala, responsible for emotional responses, are stimulated, resulting in massive excitement of the cat’s senses and perceptions, and behaviours such as drooling, yowling, purring, and writhing. It has even been suggested that catnip is a mild hallucinogenic, with intoxicated cats sometimes appearing to swat at imaginary prey. Pheromones are integral to how felines communicate both with one another and their environment, and the compound acts almost as a synthetic pheromone.

Around 10 – 20 minutes after exposure, olfactory fatigue will set in, and the catnip high will wear off and cannot be repeated until up to two hours have passed.

 Amazingly, catnip has had documented effects on even larger feline species, such as tigers, lions and leopards, but studies in this area offer varied results, the reasons for which are not yet fully understood. For example, this video shows tigers and bobcats at an American big cat rescue succumbing to the influence of catnip; whilst another study names these species as among those unaffected.

But perhaps most curious of all is that sensitivity to catnip is an inherited trait – around 33% of cats exhibit no attraction to the herb, nor any symptoms as a result of contact with it. Just as is the case with some humans, certain felines seem more prone to becoming aggressive when inebriated by catnip, with others becoming hyperactive, lackluster or exhibiting sexual behaviours. 

Unlike the human use of stimulants, however, there is no evidence to suggest that consumption of catnip leads to long-term ill-effects, be they physical or emotional. One may envy, then, the unique meeting of physiognomy and chemistry that allows our feline companions to achieve, without consequences, a perfect - and harmless - high.