Cats on catnip are clearly having a wonderful time – but does it get them high? Our vet explains more… ...

There's a very scientific reason cats go wild for catnip, and it's all about smell.

Catnip can drive kitties of all sizes a little crazy, and its effects have led feline lovers to wonder what makes this little green plant so attractive to them.

Nepetalactone, one of catnip's volatile oils, enters the cat's nasal tissue, where it is believed to bind to protein receptors that stimulate sensory neurons.

“Some cats may roll around, rub their face against the catnip, vocalize, or ‘zone out’ and lie in a relaxed state.” Like weed, the effects are different depending on how it’s consumed.

Its effect is similar to sex pheromones, which explains the writhing, rolling around and general silliness that cats exhibit under its influence. Sadly, not every cat enjoys catnip.

Not all cats are affected by the drug, but for some it can have a five- to 15-minute marijuana- kind of effect.

Cats will then be resistant to its effects for at least an hour, and if they're given catnip more than once a week or so, they can develop a kind of tolerance.